The five, at a glance
Pricing and features checked against each tool's official pricing page in August 2026. Product details change — verify before you buy.
| Tool | Starting price | Model | Best fit |
|---|---|---|---|
| Penlify | Free (5 rewrites/3 detections monthly), $2.99/mo unlimited | Flat subscription, no word credits | Individual writers checking and fixing their own drafts |
| QuillBot | Free tier, paid plans from ~$8.33/mo (annual) | Broad suite: paraphraser, grammar, summarizer, humanizer, detector | Writers who want many tools under one subscription |
| Undetectable AI | From $9.99/mo, word-credit metered | Credit-metered humanizer, detector, plagiarism, SEO writer | Heavier users who need bundled detection + plagiarism checks |
| WriteHuman | Free trial, paid plans from ~$12/mo | Word-credit metered humanizer | Users focused specifically on natural-sounding rewrites |
| Phrasly | Free tier, paid plans from ~$9.99/mo | Word-credit metered humanizer + detector | Technical or factual writing that needs careful rewriting |
Pricing reflects each vendor's publicly listed rates as of August 2026 and is not sponsored by or affiliated with any tool listed here except Penlify.
Why word-credit pricing changes the real cost
Most humanizers on this list meter usage by word count, not by month. That's fine for occasional use, but the effective cost climbs fast for anyone rewriting full essays, articles, or reports regularly — a 2,000-word document can eat a meaningful chunk of a monthly credit allowance in one pass. A flat subscription with no word cap, like Penlify's, is worth more the heavier your actual usage is; a low per-word rate is worth more if you only need a paragraph fixed once a month.
Bundled tools aren't free — you're paying for breadth
QuillBot and Undetectable AI both bundle several tools (grammar checking, plagiarism, SEO writing, image detection) into one subscription. That breadth is genuinely useful if you need several of those jobs done. It's dead weight if you only need one — rewriting a draft's tone — and you're paying suite pricing for features you'll never open.
No humanizer can promise a detector outcome
This applies to every tool on this list, Penlify included. Detectors update their models on their own schedule and disagree with each other on the same passage, so a claim like "guaranteed undetectable" is a claim no vendor can actually back up. The honest goal of a humanizer is better, more natural writing — a lower detector flag rate is often a side effect of that, not a guarantee anyone can sell.
Common questions
What's the best AI humanizer for students?
Do AI humanizers guarantee a detector will pass the text?
What's the cheapest way to humanize AI text?
Try the workflow with your own draft
Start with the private analyzer. It gives value without requiring an account or sending your text to Penlify.