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HumanizerBench

← July 2026 prompts

Business Email · Claude Sonnet 5

Business Email · written by Claude Sonnet 5 · 276 words · prompt business_email

3
passed at least 4 detectors
11
failed at least one detector
13
tools tested on this prompt
Copyleaks
hardest detector, caught 11 of 13

Input passage

Generated by Claude Sonnet 5; this exact text was pasted into every humanizer below.

Subject: Update: Annual Review Cycle Moving to April Hi Team, I want to let you know about an upcoming change to our performance review process. Starting this year, we're shifting our annual review cycle from December to April. **Why the change?** A few factors drove this decision. December is often a hectic time with holidays, year-end deliverables, and budget planning all competing for attention, which doesn't leave much room for the thoughtful, focused conversations reviews deserve. Moving to April allows us to: - Align reviews with our fiscal planning cycle for more accurate goal-setting - Give everyone breathing room during the busy holiday season - Provide more time to reflect on full-year accomplishments without year-end time pressure - Better connect performance discussions with the following year's objectives **What this means for you** Your next formal review will take place in April instead of this December. This creates a longer cycle for this transition year only — going forward, reviews will happen annually each April. In the meantime, please continue having regular check-ins with your manager about goals and priorities. Informal feedback conversations should still happen throughout the year as normal; this change only affects the timing of the formal review process. **Next steps** HR will be sending out an updated timeline with key dates in the coming weeks, including when self-assessments and manager reviews will be due. If you have immediate questions or concerns, please don't hesitate to reach out to your manager or to HR directly. Thank you for your flexibility as we make this adjustment. We believe this will lead to a more meaningful and less rushed review experience for everyone. Best, [Your Name]

How to read these scores

Each detector returns a human-likelihood on a common 0 to 1 scale, where 1 means it judged the text human-written and 0 means it flagged it as AI. On these pages a verdict counts as passed when that score is at least 0.50, the midpoint of the detector's own scale. That threshold exists only to draw the chips: the bypass rate on the leaderboard is the mean of each test's median score across the 5 detectors, a continuous number, so a tool's pass count and its bypass rate will not be the same figure.

Meaning is the input↔output embedding cosine and readability is a language-model writing-quality rating, both published per test in tests.json. Words is the output's length as a multiple of the input's; the scoring code penalizes ratios above 1.40 or below 0.60. Full definitions live in the methodology.

Humanized outputs

Ordered by how many detectors each rewrite passed; ties fall back to this cycle's rank. Each block shows what the tool returned and how the 5 detectors scored it.

StealthGPT

Rank #8 this cycle · run took 0:22

5/5 detectors passed
  • GPTZero1.00passed
  • Winston AI1.00passed
  • ZeroGPT0.85passed
  • Copyleaks1.00passed
  • Originality.ai1.00passed
Median
1.00
Meaning
89.4
Readability
55.0
Words
0.94× 276 → 260
Show output (260 words)

Fyi – We will move our Annual Review Cycle to April Team, Please be advised that we are changing our Annual Review Cycle from December to April, starting this year. The Annual Review Cycle has traditionally been held in December but this year will be April. This will allow the following benefits: Our review process will coincide with the beginning of our fiscal planning cycle, providing more time to set future goals. It will provide us a little bit of a breather from the holidays and year-end deadlines. It will allow a little more time for everyone to take a look at their whole year’s accomplishments and not get bogged down in time pressure to meet year-end deliverables. Better connects us with the next year’s objectives. This next formal review will happen in April instead of this December. For this transition year, this means a longer Annual Review cycle but in the future, each year’s reviews will be conducted in April. Please continue to have your goals and priorities discussions with your manager on an ongoing basis. Informal feedback conversations should also continue to take place throughout the year as well, this only applies to the formal annual review cycle. The updated timeline will be shared by HR in the coming weeks with key dates and timelines for the annual review cycle including when self-assessments and manager reviews will be due. If you have any questions/concerns, please feel free to reach out to your manager or to HR directly. Thank you and please be patient as we make this change.

Phrasly

Rank #9 this cycle · run took 0:21

5/5 detectors passed
  • GPTZero1.00passed
  • Winston AI0.93passed
  • ZeroGPT0.88passed
  • Copyleaks1.00passed
  • Originality.ai1.00passed
Median
1.00
Meaning
89.4
Readability
80.0
Words
1.20× 276 → 331
Show output (331 words)

Hi All -As you're aware, we've held employee reviews at the end of every calendar year. However, we've decided that for various reasons, we will change that date to April 1st effective for this year. Here's what you need to know: Why are we changing the date? December tends to be a busy time of year for everyone - holidays, end of year deliverables and targets, budget prep, etc. All of these things make it hard to dedicate the necessary time and attention to complete reviews in a thoughtful and thorough way. We hope that by moving it to April, reviews will be better able to: - Easily coincide with fiscal planning so that your goals are realistic based on budget - Allow everyone to take a breather during the hustle and bustle of December - Allow more time for reflection on the entire year's accomplishments rather than squeezing it all in before the end of the year - Tie performance conversations more closely to the upcoming year's goals How does this change affect me? If your review is currently on deck for this December, it will now take place in April. That means your review cycle this year will be 13 months - after this year, all reviews will take place in April each year. Until your formal review, you should continue to meet with your manager throughout the year to discuss your goals and priorities. We encourage informal feedback discussions throughout the year as well - this change only affects when your formal review will take place. What's next? HR will be sending out an updated review timeline with specific dates for your self assessment, manager review, etc. in the coming weeks. In the meantime, if you have any questions or concerns, please feel free to reach out to either your manager or HR. Thanks for your patience and understanding as we roll this change out. We believe this will allow for more meaningful reviews that aren't so rushed.

Undetectable.ai

Rank #2 this cycle · run took 0:18

4/5 detectors passed
  • GPTZero1.00passed
  • Winston AI0.52passed
  • ZeroGPT0.93passed
  • Copyleaks0.00caught
  • Originality.ai1.00passed
Median
0.93
Meaning
96.6
Readability
52.0
Words
1.55× 276 → 427

Output is more than 1.4× the input length, penalized as length inflation.

Show output (427 words)

Subject: Update: Annual Review Cycle Moving to April Hi Team, Our annual performance review cycle for the upcoming year will take place in April as opposed to December. **Why the change?** For reasons stated below, we are transitioning the annual performance review cycle to April as opposed to December. The fiscal planning cycle for our organization typically takes place in April for the upcoming fiscal year. It is our intent to better align our performance review processes with our organization’s fiscal planning cycle for more accurate goal setting and planning. Additionally, the end of the year is typically a busy time for individuals and organizations alike to complete year end tasks and to plan for the budget for the upcoming year. We want to complete our performance review processes for our employees without the additional pressures of the busy holiday season. We believe that these thoughtful and focused conversations are so very important and can be compromised during the very busy holiday season. These review processes will now better enable us to connect performance discussions with the following year’s objectives. - Allow reviews to align with our fiscal planning cycles for more accurate setting of goals. - To allow more time for everyone to prepare for their review without having to go through the holiday end of end of year work. - Allow more time to review the full year of work, and set the most accurate goals for the following year. - Allow for better correlation between performance review and subsequent year’s goals. **What this means for you** Your next formal review will be held in April instead of this December. For this transition year only we will extend the formal review period to the full year for you to reflect on your accomplishments, and then move to hold annual reviews every April thereafter. Your continued regular meetings with your manager to review your goals and discuss priorities, etc. and have informal feedback sessions throughout the year will remain unchanged. This change only pertains to the formal review process. **Next steps** An updated timeline for the annual review process will be distributed in a few weeks and will include key dates for when you can expect to receive your self-assessment and your manager’s review. If you have any immediate questions or concerns, please reach out to your manager or to HR. Thanks to everyone for their time and effort to complete annual reviews, and for their understanding with changes that will I believe bring many positives as we continue to review and grow. Best, [Your Name]

WriteHuman

Rank #1 this cycle · run took 0:20

3/5 detectors passed
  • GPTZero0.69passed
  • Winston AI0.00caught
  • ZeroGPT1.00passed
  • Copyleaks0.00caught
  • Originality.ai1.00passed
Median
0.69
Meaning
93.9
Readability
55.0
Words
1.14× 276 → 314
Show output (314 words)

Subject: Change to Annual Review Cycle Hi Team, I would like to give everyone notice of a changewith the annual review cycle. Beginning this year, we will move the annual review cycle from December to April. **What is behind this changewith the annual review process?** There are a few reasons for this change. December is a busy month with end of year holiday tasks, end of year deliverables, and end of year budget planning. We don't have the time or mental focus that the performance reviews require in order to have the discussions we need. Shifting the reviews to April means we have time to: - integrate the reviews with the planning cycle for the FY which allows more precise reviews for performance - allow everyone to have time to relax during the busy holiday season - give everyone full time to reflect on the accomplishments of the year with no time pressure constraints - integrate performance reviews with the priorities and focus of the new performance year **What does this changewith the annual review cycle mean for you?** The formal review you would have received in December will take place in April this year. For this year only, the review cycle will be extended. For all subsequent years, the performance reviews will take place in April annually. As before, informal reviews and progress check meetings to discuss goals will continue to happen. The only change is with the formal review cycle. **What now?** The HR department is in the process of drafting a new performance review process with dates and will distribute it soon. In the mean time, if you have questions of a more general nature, reach out to HR. If you need to discuss process, reach out to your line manager. Thanks! Thanks for accommodating this change. We're certain this ensures a proper review for everyone without rushing. Best, [Your Name]

Stealth Writer

Rank #4 this cycle · run took 0:16

2/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.23caught
  • ZeroGPT0.93passed
  • Copyleaks0.00caught
  • Originality.ai0.99passed
Median
0.23
Meaning
90.0
Readability
42.0
Words
1.15× 276 → 318
Show output (318 words)

Raising Standards and upholding High Expectations, Primary Curriculum, Subject: Update: Annual Review Cycle Moving to April Hi Team, I thought I'd update you on a change that will soon be happening in our performance reviews system. The review process is now changing from December to April each year. **Why the change?** This decision was influenced by a couple of factors. December can be a busy and busy month, with holiday season, year-end deliverables, and budget planning dominating the conversation – it's hard to find time for the considered and focused conversations that reviews deserve. By relocating to April we can: - Link reviews to our fiscal planning process to inform better goal setting During the busy holiday season, allow everyone plenty of breathing room: - Allot more time to contemplate on the successes of the entire year not having the pressures of year-end sales - Improve tie-in of performance discussions to next year's goals This will help you understand what this means for you. You will have another formal review in April not this December. This provides a longer cycle for this transition year only and, moving forward, reviews will occur yearly in April. There should be continued regular check-ins with your Manger in the meantime with respect to goals and priorities. This change does not mean that informal feedback conversations between you and your mentee will not take place as usual, but that the formal process for review will be happening at this time of year. **Next steps** A new timeline of key dates should be sent out by HR in coming weeks, and will include when self-assessments and manager reviews are due. Please feel free to contact your manager, or HR directly, if you have any questions or concerns. Many thanks for your support through this change. We hope that will bring a more enriching and not so hurried review process for all. Best, [Your Name]

HIX Bypass

Rank #6 this cycle · run took 0:15

2/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.73passed
  • ZeroGPT1.00passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
95.0
Readability
45.0
Words
1.05× 276 → 289
Show output (289 words)

From: Annual Review Cycle Shift to April Hi Team, In this post, I want to inform you of an imminent change we are making to the performance review process. So this year we are changing our annual review cycle from December to April. Why the change? Several reasons led up to this decision appegs.com. No wonder that December tends to become a busy time with holidays, year end deliverables and budget planning all vying for attention. There is hardly room left for the thoughtful, focused conversations reviews need! Moving to April allows us to: – Spend reviews in the same cadence as our fiscal planning cycle for more accurate goal-setting Give everybody some space with busy holidays period Extra time to think through what the year brought, sans post-Q4 pressure Tie performance conversations more directly to the goals for next year What this means for you The next time you will have a formal review is in April, rather than this December. This makes for one longer cycle this year only — thereafter, reviews will take place annually every April. In the meantime, be sure to continue touching base with your manager regularly on goals and priorities. This change only affects the timing of formal review process — informal feedback conversations should continue throughout the year as normal. Next steps Using the format of key dates, an updated timeline will be sent by HR in weeks ahead; this includes due self-assessments and manager reviews. If you have any questions or concerns please reach out to your manager, or HR directly. We appreciate your flexibility as we make this transition. We feel this way there will be a less rushed and more meaningful review process for everyone. Best, [Your Name]

Walter Writes

Rank #7 this cycle · run took 0:23

2/5 detectors passed
  • GPTZero1.00passed
  • Winston AI0.00caught
  • ZeroGPT0.76passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
86.6
Readability
68.0
Words
1.37× 276 → 379
Show output (379 words)

Subject: upcoming: the performance review process will change in april Hello all, I wanted to inform everyone that there are some changes planned to the process used for conducting performance evaluations. For this calendar year, we will begin evaluating employee performance at the end of april (previously it was in december). **why the change?** Several items led to the development of this plan. The month of december is a very hectic month due to many issues such as: holidays, closing out the prior years' activities/budgets, planning for new budgets, etc. Many of these tasks require a lot of effort and time. It would be difficult to find the time for a productive performance evaluation conversation given the amount of work being completed by employees and management. By changing the review date to april we can accomplish several things. These include: 1. Aligning the review with the company’s fiscal planning Cycle so that goals are more accurately set based on the company's financial situation. 2. Providing employees additional time to focus on their job responsibilities without the added stress of the holidays. 3. Giving employees adequate time to reflect on what they accomplished over the course of a full year without feeling pressured by year-end deadlines. 4. Creating a better opportunity to discuss performance over the past year and how those results align with the next year's objectives. **how does this affect you?** The first formal review under this new schedule will occur in april rather than in december. Please note that this is only true for this transitional year. After this year, the annual reviews will continue to take place every april. You may want to schedule informal feedback sessions with your supervisor regarding your current goals and priorities, just like before. The main difference is simply the timing of the formal review process. **upcoming next steps** In the near future, human resources will send you an e-mail containing an updated timeline for reviews, along with specific dates for both self-assessment and manager reviews. If you need clarification or guidance prior to receiving that information, do not hesitate to contact either your manager or human resources. We appreciate your understanding as we implement this change and hope you see it as an opportunity to improve the performance review process.

Humanize AI Pro

Rank #3 this cycle · run took 0:14

1/5 detectors passed
  • GPTZero0.37caught
  • Winston AI0.01caught
  • ZeroGPT0.97passed
  • Copyleaks0.00caught
  • Originality.ai0.02caught
Median
0.02
Meaning
94.3
Readability
58.0
Words
0.96× 276 → 266
Show output (266 words)

Subject: Update: Annual Review Cycle Moving to April Hello Team, I wanted to share with you an upcoming change to our performance review cycle. Beginning this year, our annual review process will be moving from December to April. **Reasons for Change** There were several reasons that made us change the cycle date. First of all, December is a very busy month with the holidays, year-end deadlines and budgets planning, so there will be not enough time for thoughtful and focused discussion required for this process. The April date will help us to: - Harmonize our review cycle with the fiscal planning period for better setting of goals - Provide some relief in a very busy holiday period - Reflect on accomplishments of the full year without being pushed by year-end deadlines - Connect performance discussions with next year’s goals **How does it affect you** Next time you will be undergoing a formal performance review this April, rather than this December. So, for this year there will be a longer review cycle – but in future the review process will occur annually each April. During this time, you are supposed to have informal meetings with your manager to discuss goals and priorities. In addition to that, the informal feedback process will remain unchanged throughout the year. **What’s Next** Our HR will provide the new timeline with the important dates in the coming weeks, including the deadlines for self-assessments and manager reviews. You may contact your manager or HR department in case of any questions arising now. Thank you for your understanding of the situation. Sincerely, [Your Name]

Humbot

Rank #5 this cycle · run took 0:30

1/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.00caught
  • ZeroGPT0.94passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
97.4
Readability
45.0
Words
1.17× 276 → 324
Show output (324 words)

Subject: **Update Annual Review Cycle Shifting to April Hi Team, I wanted to inform you of a change that will be coming to our performance review process. We are moving from an annual review in December to one in April, starting this year. Why the change? There were a few reasons that led me to this decision. If you know anything about this time of year, December can often be a busy month: holidays to juggle, year-end deliverables and some budget planning that all demand our attention — not leaving much room for the thoughtful, focused conversations reviews are due. Moving to April allows us to: Sync with our fiscal planning process so that we can set more realistic goals Allow others breathing space during the hectic holiday season Now you are working with a set of topics, which will give you more time to think about your full year without the need to rush it at the end of December Link performance conversations better to the next years goals What this means for you Instead of this December, your next formal review will be in April. This effectively extends the cycle for this transition year only - from next year onwards a review will happen every April. For now, just keep having regular check-ins with your manager about goals and priorities This only has an impact on when the formal review process runs — informal feedback conversations can still continue throughout the year in the same way they do now. Next steps HR will be communicating a new timeline with important dates over the coming weeks, including when self-assessments and manager reviews are due. If you have any immediate questions or concerns, please reach out to your manager directly -- or feel free to speak with HR. We appreciate your patience as we implement this transition. We thought this would enable to users a more meaningful and less rushed experience. Best, [Your Name]

AI Humanize io

Rank #10 this cycle · run took 0:26

1/5 detectors passed
  • GPTZero0.24caught
  • Winston AI0.00caught
  • ZeroGPT0.72passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
95.3
Readability
62.0
Words
1.25× 276 → 346
Show output (346 words)

Subject: Change to Annual Review Cycle Date Team, I wanted to share an update about a change to our annual performance review process. This year, the annual review cycle will move from December to April. **Why are we changing the dates?** Several factors contributed to this decision. Much of December is consumed by Christmas holidays and year-end projects and budgets, making it challenging for us to have enough time to have the level of quality, deep thought, and the concentration needed for the discussions that should happen during the review process. Moving the reviews to April allows us to: - Align our review process better with our fiscal planning cycle so that we have better alignment between goals and objectives - Provide everyone with additional time to complete objectives without being under pressure of deadlines during the holidays - Provide greater time to reflect on one's accomplishments from the previous year without the time pressure of the holiday season - Better connect review discussions with the goals and objectives for the next year **What will this change mean for you?** The next performance review will be held in April rather than in December. Therefore, this will result in your review cycle that was previously done every December will be done every April going forward. In the meantime, continue to meet with your supervisor about your objectives and priorities on a regular basis. Managers should still be providing informal feedback to employees throughout the year; changes only affect the timing of the formal review process. **Next Steps** The HR department will be providing communications regarding the new timeline and key dates, including the deadlines for self-assessments and managers conducting reviews; this information will be shared in the next few weeks. If you have any questions or concerns, please do not hesitate to contact your supervisor or HR directly. I appreciate your patience and flexibility during this transition. Our goal is to improve the quality of the review process for everyone involved by allowing for more in-depth discussions while creating a better experience for everyone. Regards, [Your Name]

Super Humanizer

Rank #11 this cycle · run took 0:12

1/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.00caught
  • ZeroGPT0.75passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
94.9
Readability
78.0
Words
1.10× 276 → 303
Show output (303 words)

Subject: Notice: Performance Reviews Shifting to April This Year! Hey Everyone, I wanted to give you a heads-up on a shift we’re making to our annual performance review cycle. Beginning this year, we’ll be moving our review cycle from December to April. So why the move? Well, let's be honest. December is a bit… intense. You've got holiday buzz, year-end tasks piling up, and budgeting for the next year all hitting you at once – there’s not a whole lot of space left for meaningful, introspective review conversations. By moving things to April we can: Better align reviews with our fiscal planning for clearer goals. Create breathing room for everyone during the holiday rush. Allow more time to fully reflect on your year's accomplishments without end-of-year urgency. Help more clearly link past performance to the upcoming year's targets. So what does this mean for you? Your next formal review will happen in April rather than December this year. This means your review cycle is just a little longer this year, as we transition. Reviews will be on an annual cycle every April from here on out. In the interim, make sure you continue to have regular check-ins with your manager on your progress and priorities. Informal discussions about performance and feedback will continue as always – it’s just the formal review cycle timing we’re adjusting. Next Steps: HR will share a more detailed timeline with important dates in the coming weeks, including when self-assessments and manager reviews will be due. In the meantime, please don't hesitate to ask your manager or the HR team if you have any immediate questions or concerns. Thanks so much for your adaptability with this change – we’re confident it will result in a more valuable and less stressful review process for all of us! Best, [Your Name]

NoteGPT

Rank #13 this cycle · run took 0:22

1/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.00caught
  • ZeroGPT0.82passed
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
97.7
Readability
85.0
Words
0.93× 276 → 257
Show output (257 words)

Subject: Update: Annual Review Cycle Moving to April Hi Team, I want to share a quick heads up about a change to our performance review process: we’re moving our annual reviews from December to April, starting this year. Why are we making this shift? Honestly, December is a whirlwind. With holidays, year-end deadlines, and budget planning, it’s tough to fit in productive, thoughtful review conversations. Shifting to April should help in a few ways: - Reviews will line up with our fiscal planning, so goal-setting feels more relevant - Everyone gets a break from year-end crunch and the holiday rush - There’s more space to really reflect on the year’s work—without the pressure of December’s packed schedule - We’ll be able to tie performance discussions more closely to goals for the following year What’s changing for you? The next formal review is in April, not this December. This means one longer stretch for this year only. After that, reviews will settle into an April cycle every year. Nothing else about feedback should change—keep meeting with your manager and checking in on goals like you always do. This only affects the timing of the official review. What's next? HR will send a new timeline soon, including when self-assessments and manager reviews are due. If you have any questions or need to talk things through, reach out to your manager or HR any time. Thanks for rolling with this change. We’re making the switch because we believe it’ll lead to better, less rushed reviews for everyone. Best, [Your Name]

Grammarly

Rank #12 this cycle · run took 0:11

0/5 detectors passed
  • GPTZero0.00caught
  • Winston AI0.00caught
  • ZeroGPT0.19caught
  • Copyleaks0.00caught
  • Originality.ai0.00caught
Median
0.00
Meaning
99.2
Readability
84.0
Words
0.95× 276 → 261
Show output (261 words)

Subject: Update: Annual Review Cycle Moving to April Hi Team, I want to inform you about a change to our performance review process. Starting this year, we are moving our annual review cycle from December to April. **Why the change?** Several factors influenced this decision. December is usually a busy time with holidays, year-end tasks, and budget planning, which makes it hard to have the focused discussions that reviews deserve. Moving to April helps us: - Connect reviews to our fiscal planning cycle for better goal-setting - Give everyone space during the busy holiday season - Provide more time to reflect on yearly accomplishments without end-of-year pressure - Link performance discussions to the next year's objectives more effectively **What this means for you** Your next formal review will happen in April instead of this December. This means a longer cycle for this transition year only; in the future, reviews will take place annually each April. In the meantime, please keep having regular check-ins with your manager about goals and priorities. Informal feedback conversations should continue throughout the year as usual. This change only affects the timing of the formal review process. **Next steps** HR will send out an updated timeline with key dates soon, including when self-assessments and manager reviews are due. If you have any immediate questions or concerns, please feel free to reach out to your manager or HR directly. Thank you for your flexibility as we make this adjustment. We believe this will lead to a more meaningful and less rushed review experience for everyone. Best, [Your Name]

Session recording