WriteHuman and Undetectable AI are both dedicated AI humanizer tools that actually work. Undetectable AI is the bigger platform with more features: readability and purpose presets, a multi-detector panel, and more add-on tools. WriteHuman is leaner, with a simpler interface. Both have a Chrome extension and a developer API, and neither offers a generous free tier. Here's the full comparison, plus why HumanizeThisAI is worth considering as an alternative to both.
Disclosure: This comparison is published on the HumanizeThisAI blog. We compete directly with both tools. We've aimed for accuracy and fairness, but verify independently. Pricing and features last checked October 2026.
Quick Verdict
Choose WriteHuman if you want a straightforward humanizer with a simple interface and per-request pricing.
Choose Undetectable AI if you need maximum flexibility: five readability levels and nine purposes, a multi-detector panel, or enterprise scaling.
Consider HumanizeThisAI if you want a real free tier (1,000 words/month with a free account), a lower entry price, and high bypass rates without the complexity. More on that at the end.
How Do WriteHuman and Undetectable AI Compare on Features?
| Feature | WriteHuman | Undetectable AI |
|---|---|---|
| Free Tier | 3 requests/month, 250 words each | Free Basic model; 250-word, 3-day trial |
| Starting Price | $20/mo (Basic, 80 requests) | $9.99/mo (10K words) |
| Mid-Tier Price | $29/mo (Pro, 200 requests) | $19/mo (20K words) |
| Top Tier Price | $59/mo (Ultra, “unlimited” with monthly caps) | Scales to 380K words |
| Annual Discount | From $12/mo (billed yearly) | From $5/mo (billed yearly) |
| Humanization Modes | 8 tone presets (Standard, Academic, Casual and more) | 5 readability levels, 9 purposes |
| Built-in AI Detector | Yes | Yes (multi-detector panel) |
| Chrome Extension | Yes | Yes (50+ sites) |
| Developer API | Yes (from $29/mo) | Yes (from $29/mo) |
| Word Limit per Request | 250-3,000 words (by plan) | Up to 10,000 characters |
| Money-Back Guarantee | No (non-refundable; cancel anytime) | Word credits back if output scores under 75% human |
| Additional Tools | Humanizer, detectors, MCP server | SEO writer, essay writer, job applier, style replicator API |
How Does Pricing Work for Each Tool?
WriteHuman and Undetectable AI use fundamentally different pricing models, which makes direct comparison tricky.
WriteHuman Pricing
WriteHuman charges by number of requests with per-request word limits:
- Basic: $20/month ($12/month yearly) for 80 requests, 600 words per request (up to 48,000 words total)
- Pro: $29/month ($19/month yearly) for 200 requests, 1,200 words per request (up to 240,000 words total)
- Ultra: $59/month ($39/month yearly) for “unlimited” requests (monthly caps apply), 3,000 words per request
- Free: 3 requests/month, 250 words per request
Undetectable AI Pricing
Undetectable AI charges by monthly word bank:
- Monthly: Starts at $9.99/month for 10,000 words ($19 for 20,000), as of Oct 2026. Higher volumes available up to 380,000 words.
- Annual: Starts at ~$5/month for 10,000 words (billed at $60/year). Scales up to 380,000 words on annual plans.
- Trial: 250 words over 3 days. Requires account creation.
The Math That Matters
If you're humanizing around 10,000 words per month: Undetectable AI costs $9.99/month (or $5/month annual). WriteHuman's Basic plan at $20/month gives you up to 48,000 words, which is better value per word only if you use most of your requests. If you max out the 600-word limit per request, 80 requests gets you 48K words. If your documents are longer, you burn through requests faster and may need the $29/month Pro plan.
Where WriteHuman Wins
Simpler Interface
WriteHuman is a focused tool: paste text, pick a tone if you want one, humanize, done. There's no feature overload and few adjacent tools competing for attention. If you want simplicity, WriteHuman delivers it. Undetectable AI's readability and purpose settings can be powerful for experienced users, but they also create decision fatigue for newcomers.
Transparent Per-Request Pricing
With WriteHuman, you know exactly how many requests you have and how many words each can handle. Undetectable AI's word bank system is simpler in theory but makes it harder to predict cost-per-document. WriteHuman also lets you cancel, upgrade, or downgrade anytime with no contracts.
Where Undetectable AI Wins
Chrome Extension
This is Undetectable AI's biggest practical advantage. Their Chrome extension works across Gmail, Google Docs, LinkedIn, ChatGPT, Claude, Notion, Medium, WordPress, and 50+ other sites. You can humanize text directly where you write it. WriteHuman's extension works in a side panel instead.
Writing Modes
Five readability levels (High School, University, Doctorate, Journalist and Marketing) and nine purposes (from Essay and Story to Cover Letter) let you tailor the output to your use case. A blog post and a university essay need different humanization approaches, and Undetectable AI acknowledges that. WriteHuman offers tone presets (including Academic) but fewer controls.
Multi-Detector Panel
After humanization, Undetectable AI shows you estimated scores from GPTZero, Copyleaks, ZeroGPT and other detectors simultaneously. WriteHuman has a built-in detector, but it's a single-detector check. Seeing multiple detector scores in one view saves time and gives more confidence.
Platform Ecosystem
Undetectable AI has expanded into an AI SEO writer, essay writer, job application automation, and a writing style replicator API. If you want multiple AI tools under one subscription, Undetectable AI offers more. WriteHuman sticks mostly to humanization and detection.
Which Tool Has Better Bypass Rates?
Both tools claim high bypass rates, but those are their own numbers. Independent testing of detectors tells a more nuanced story.
The honest assessment: neither tool hits 100% across all detectors, and any tool that claims otherwise isn't being straight with you. For a deeper look at what's really going on under the hood, read how AI detectors work.
Undetectable AI promises a refund if output is flagged. That sounds great on paper, but its Terms give back word credits only when a result provably scores under 75% human, claimed within 30 days. WriteHuman doesn't make a bypass guarantee but lets you cancel anytime. Both approaches have merits — test with your specific content before committing to either.
Who Should Pick Which Tool?
Best for Students
Edge: Undetectable AI. The University and Doctorate readability levels and Essay purpose target academic content, which is the hardest type to humanize. The annual pricing at $5/month is also student-friendly. WriteHuman's $20/month Basic plan is pricier. See our best AI humanizer for students guide for more student-focused comparisons.
Best for Content Writers
Edge: WriteHuman. The simpler workflow suits production work. The Pro plan at $29/month with 200 requests and 1,200 words per request covers most content writers' needs. The simpler workflow (paste, humanize, copy) is efficient for production work.
Best for Agencies and Developers
Edge: Undetectable AI. The scalable word bank (up to 380,000 words a month) and custom For Business pricing suit teams that need volume. WriteHuman launched its own API in March 2026, so compare both if you build integrations.
Best on a Budget
Depends on usage. Undetectable AI's annual plan at $5/month for 10K words is the cheapest entry point between the two. But WriteHuman's Basic plan at $20/month potentially gives you more total words if you fully use all 80 requests. Neither tool offers a generous free tier — WriteHuman gives 3 requests of 250 words per month, Undetectable AI gives 250 words of its stronger models that expire after 3 days.
The Third Option: HumanizeThisAI
We built HumanizeThisAI because we saw gaps in both of these tools. Here's where we fit in:
| Factor | WriteHuman | Undetectable AI | HumanizeThisAI |
|---|---|---|---|
| Free Tier | 3 req/month (250 words each) | Free Basic model; 250-word, 3-day trial | 1,000 words/month with a free account (resets monthly) |
| Cheapest Paid Plan | $20/mo ($12/mo annual) | $9.99/mo ($5/mo annual) | $5.99/mo ($2.99/mo annual) |
| Academic Mode | Yes (Academic tone) | Yes (University readability level) | Yes (For essays mode, Starter and up) |
| Built-in Detector | Yes | Yes (multi-detector) | Yes |
| Languages | 40+ | 50+ | 12 (Creator and up) |
The advantage we offer over both tools comes down to three things:
- A real free tier. 1,000 words/month with a free account, no countdown timer. Test the quality without committing anything. Neither WriteHuman (750 words a month) nor Undetectable AI (a 250-word trial of its stronger models) offers this much.
- Lower pricing. Our Starter plan at $5.99/month ($2.99 annual) undercuts both tools. At the Creator level ($19.99/month for 80K words), we're competitive with WriteHuman's Pro plan while offering a clear word count instead of a request limit.
- Semantic reconstruction. Our humanizer rebuilds text at the meaning level rather than paraphrasing or applying surface-level transformations. We address the actual statistical patterns that detectors measure.
We don't have Undetectable AI's readability and purpose presets. If that matters to you, Undetectable AI is the better choice. But for most users who want reliable humanization at a fair price, we think HumanizeThisAI delivers more value. Read our full comparison of the best AI humanizer tools for prices, free tiers and features across 15 tools.
TL;DR
- Undetectable AI wins on features: readability and purpose presets, a multi-detector panel, and more add-on tools. Best for agencies and students who want academic presets.
- WriteHuman wins on simplicity: straightforward per-request pricing and a simpler interface. Best for individual content writers.
- Neither offers a generous free tier: WriteHuman gives 3 requests of 250 words/month; Undetectable AI gives 250 words of its stronger models that expire after 3 days.
- HumanizeThisAI lets you try it free with no signup (200 words per run), gives 1,000 words/month with a free account, has lower paid pricing starting at $5.99/month, and 99%+ bypass rates via semantic reconstruction. It is worth testing alongside both.
Final Verdict
WriteHuman and Undetectable AI are both legitimate tools that serve different user profiles. WriteHuman is the better choice for individual users who value simplicity. Undetectable AI is the better choice for power users, agencies, and developers who need flexibility and scale.
Both have weaknesses. Neither offers a truly generous free tier — WriteHuman's 3 monthly requests and Undetectable AI's 3-day trial are both restrictive. WriteHuman has fewer presets than power users may want.
The best approach: test all three. Use HumanizeThisAI's free runs (200 words each, no signup needed). Use WriteHuman's 3 free requests. Use Undetectable AI's 250-word trial. Run the same text through all three and compare the output side by side. The tool that produces the best result for your content is the one you should use.
Related Comparisons
- HumanizeThisAI vs Undetectable AI: Honest Comparison for 2026 — our detailed head-to-head with Undetectable AI
- Best AI Humanizer Tools 2026: 15 Free and Paid Options Compared Results — 10 tools tested head-to-head
- Can Turnitin Detect Humanized AI Text? : what Turnitin says it can detect in 2026
Try the tool both of these compete with. Paste up to 200 words into HumanizeThisAI, no signup, no credit card. Compare the output against WriteHuman and Undetectable AI yourself. That's the only comparison that counts.
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