Metric37 vs QuillBot Humanizer: Comparison (2026)
Compare Metric37 and QuillBot Humanizer. LLM-based rewriting vs synonym swapping, pricing, and output quality differences.
| Feature | Metric37 | QuillBot Humanizer |
|---|---|---|
| Rewriting method | Rewrite + quality scoring loop | Paraphrasing modes (word and phrase substitution) |
| Quality scoring | Automatic human score (0-100) on every rewrite | No score on rewrites; separate AI Detector tool |
| Version history | Up to 20 versions with word-level diffs | Humanize history list, no diffs |
| Iterative refinement | Re-humanize and re-score unlimited times | Manual re-paraphrasing, no scoring loop |
| Tone and style options | Tone selection per rewrite | 2 modes free; 9 modes plus custom modes on Premium |
| Input limit per request | Up to 100,000 characters per request | 125 words free with a daily use cap; unlimited on Premium |
| Meaning preservation | High; context-aware rewriting | Variable; word swaps can shift meaning |
| Free tier | 1,500 words (on signup) | Free plan with 125-word paste cap |
| Pricing model | One-time word packs, never expire | Subscription (Free, Premium, Team) |
| Starting paid price | $2 pack (3,000 words) | Premium subscription, priced by region and billing cycle |
| API access | Yes (REST API with key auth) | No humanizer API advertised |
| Plagiarism checker | Not included | 25,000 words/month on Premium |
A paraphraser and a humanizer are not the same job
QuillBot built its reputation on paraphrasing, and at that job it is genuinely good. You paste a passage, pick a mode, and get a reworded version that says roughly the same thing. The AI Humanizer is an extension of that engine: by QuillBot's own description, it adjusts word choice and refines sentence structure while keeping the original meaning intact.
Humanizing AI text asks for more than that. Detectors flag statistical regularities in rhythm, sentence length, and structure, and those regularities usually survive a reworded draft. A paraphrased ChatGPT essay is still a ChatGPT essay in different clothes.
Metric37 approaches the problem from the measurement side. Every rewrite comes back with a human score from 0 to 100, and rewrites that fall short get retried before you ever see them. You are not trusting that the text became more human. You can read the number.
Where QuillBot is the better choice
QuillBot does a lot well. If you want one subscription covering paraphrasing, grammar checking, summarizing, translation, and plagiarism detection, QuillBot Premium is hard to beat. It is a mature product from the Learneo family with years of polish behind it, including ChatGPT and Gemini integrations for Premium users.
It is also the stronger pick for multilingual work. The humanizer supports English in four dialects (US, UK, AU, CA) plus Spanish, French, German, and Portuguese, and the paraphraser covers 23 languages. Metric37 does not compete on language breadth.
Heavy daily users get real value too. Premium removes the caps entirely, with unlimited paraphrasing and unlimited humanizer usage for a flat fee, plus nine paraphrase modes and the option to build custom ones. If you rework short passages all day, every day, an unlimited subscription beats paying per word.
Where Metric37 is the better choice
If the goal is AI text that holds up to scrutiny, the scoring loop is the difference. Metric37 grades every rewrite from 0 to 100 and automatically retries low scores. QuillBot hands you a reworded draft and leaves the judging to you, or to its separate AI Detector tool.
Document length is the second gap. QuillBot's free humanizer takes 125 words per paste, with a daily use cap on top, which turns a 2,000-word essay into sixteen separate copy-paste operations. Metric37 accepts up to 100,000 characters in a single request, so full articles and reports go through in one pass with a consistent voice.
Then there is the working history. Metric37 retains up to 20 versions of every document and shows word-level diffs between any two, so you can see exactly what each rewrite changed and roll back when needed. QuillBot keeps a humanize history list of past outputs, but with no diffing and no scores attached. And if you automate content work, Metric37 ships a REST API; QuillBot does not advertise a humanizer API at all.
Pricing comparison
QuillBot runs a classic freemium subscription. The free plan is deliberately small: short per-paste limits on both the paraphraser and the humanizer, two paraphrase modes, and a daily ceiling on humanizer use. Premium lifts those limits to unlimited and unlocks the full mode list. QuillBot prices Premium by region and billing cycle, so check quillbot.com for the current rate where you live; a Team plan with custom pricing covers organizations.
Metric37 skips subscriptions entirely. You start with 1,500 free words when you create an account, then buy one-time packs as needed: $2 for 3,000 words, $4 for 10,000, $12 for 50,000, or $39 for 200,000. Packs never expire, and re-scoring an existing result costs nothing.
Which model wins depends on your usage shape. If you live inside a writing suite every day, QuillBot's flat fee spreads across many tools and earns its keep. If you humanize in bursts, a few documents this week and nothing for a month, paying once for words you keep forever is cheaper than a subscription you forget to cancel.
How to evaluate any humanizer
Skip the marketing pages and run a test. Take one 500-word sample of AI-generated text on a topic you know, run it through every tool on your shortlist, and check three things in order. First, does the output pass the specific detectors you will actually face, not just the ones the vendor screenshots? Second, does it still sound like a person? Read it out loud and listen for filler. Third, did the meaning survive, especially numbers, names, and claims?
Then look at the workflow around the rewrite. Can you see a quality measure, or are you guessing? Is there a history you can return to next week? Does a per-paste cap force you to chop documents into fragments and stitch them back together?
Finally, ignore headline prices until you know your own volume. Pull a number from your last three months of actual writing, work out what each tool on your shortlist would have charged for it, and compare those figures instead.
Our verdict
QuillBot is a strong writing suite and the better buy if you need paraphrasing, grammar, translation, and plagiarism checks in one subscription, or if you work in languages beyond English. As a dedicated AI humanizer it is thinner: tight per-paste limits on the free plan, no scoring on rewrites, and no humanizer API. For making AI text read human, and proving that it does, Metric37 is the stronger tool.
Frequently asked questions
- Is Metric37 better than QuillBot for humanizing AI text?
- For AI humanization specifically, yes. QuillBot is primarily a paraphrasing tool that swaps words and restructures phrases, which can still get flagged by AI detectors. Metric37 uses LLM-based rewriting that preserves meaning while genuinely changing the statistical patterns detectors look for, and it scores every output so you can verify the result.
- Does QuillBot have an AI humanizer?
- Yes. QuillBot offers a dedicated AI Humanizer with a 125-word limit per paste and a daily use cap on the free plan, and unlimited usage on Premium. What it lacks is a quality loop: it does not score how human each rewrite sounds or retry when a rewrite is weak. Metric37 includes automatic scoring and iterative refinement on every output.
- Which tool preserves meaning better?
- LLM-based rewriters like Metric37 understand context and preserve meaning with high fidelity. Word-substitution tools like QuillBot can introduce awkward phrasing or change the intended meaning, especially in technical or nuanced content. Swap 'significant' for 'considerable' in a statistics writeup and you have quietly changed the claim, which is exactly the kind of slip a context-aware rewrite avoids.
- How much does QuillBot Premium cost?
- QuillBot prices Premium regionally and by billing cycle (monthly versus annual), so the exact figure depends on where you are; check quillbot.com for your local rate. Metric37 has no subscription at all: one-time word packs start at $2 for 3,000 words and never expire.
- Does QuillBot's humanizer work in languages other than English?
- In several, yes, and this is where QuillBot genuinely pulls ahead. You can humanize text in Spanish, French, German, and Portuguese as well as English, with separate handling for US, UK, Australian, and Canadian usage, and the paraphraser reaches further still into 23 languages. Metric37 cannot match that breadth, so if you publish outside English, QuillBot is the safer pick.
- Do I need a subscription to use Metric37?
- No. Metric37 gives every new account 1,500 free words with no credit card, then sells one-time word packs from $2 (3,000 words) up to $39 (200,000 words). Words stay in your account until you use them, so there is nothing to cancel.
Try Metric37 free
1,500 words on signup, no credit card required. See how it compares to QuillBot Humanizer on your own text.
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