HumanPen vs GPTHuman: a text humanizer with a detector, or your Word file handed back
Once you log in, GPTHuman can import a .docx or PDF, pulls the text out, and gives you a result to copy. HumanPen rewrites inside your .docx or .pptx and hands the file back.
Competitor details verified 2026-09-11. Their own site is the authority.
The short answer
GPTHuman is a text humanizer for dozens of languages, with an AI detector and a paraphraser on the same site and a public API and MCP server. It suits pieces you paste in and copy out that fit under its per-output word cap, like a few paragraphs or a short essay. HumanPen works inside an English .docx or .pptx, can follow a Turnitin or iThenticate report, and hands the file back.
Side by side
| HumanPen | GPTHuman | |
|---|---|---|
| Input | Upload the document itself | Paste text. Its help center says that after you log in you can Import from file (.docx or .pdf), and it will "automatically extract the text from your file"; logged out, the homepage shows only a paste box |
| Output | The same file back, still editable | Text in the right-hand panel, copied with the clipboard icon |
| Per-request word cap | None | Counted per output: Free 300 / Starter 1,000 / Plus 1,500 / Unlimited 2,500 words; API input 250 characters to 2,500 words |
| Detection report import | Turnitin / iThenticate, flagged passages only | Not stated |
| Word-count control | Set a target word range; output converges on it, slight drift possible | Not stated (a word counter turns red past your plan's limit) |
| Billing | Metered credits, never expire | Monthly or annual subscription counted in output words (its help center calls them credits, usually 1 word = 1 credit); API credits are bought separately in packages, and its API page says they never expire |
| Adjacent tools | Citation fix, condense, translate | AI detector (1,800 characters without an account; the full assessment needs sign-up), Paraphraser, Human Content Generator |
| Agent / API integration | Skill, MCP, and REST API — callable from AI agents | REST API (POST /v1/humanize, docs readable without an account, key after sign-up) and an MCP server (@gpthuman/mcp-server, plus a hosted MCP endpoint) |
| Rewrite languages | English only | Its homepage says 80; its pricing and API pages say 50+ |
When to pick GPTHuman
- You write in a language other than English. GPTHuman covers dozens of languages; HumanPen only works in English.
- You want to check and rewrite in one place. GPTHuman has its own AI detector, and each rewrite shows a Human Score, which is GPTHuman's own rating, not a detection report. HumanPen has no detector and gives no score: you bring a Turnitin or iThenticate report, or pick the passages yourself.
- You want to set the tone and how far the rewrite strays. Tone has Standard, High School, College and PhD; Mode has Professional, Balanced and Enhanced, and Professional is described as staying closer to the original.
- Your agent passes plain text around, not files. GPTHuman's MCP server has a single tool, humanize_text, that takes the text itself along with tone and mode.
- Your piece fits in one output: a few paragraphs, an email, a short essay. Paste it in, rewrite, copy it out.
A Word file goes in. What comes back?
Once you're logged in, GPTHuman can import a .docx or PDF. Its help guide takes it from there: the text is pulled out of the file, the humanized version appears in the right panel, and you copy it with the clipboard icon. The guide doesn't say whether you can download an edited file. GPTHuman is also upfront about what needs care: "Lists, tables, source code, equations, legal language, direct quotations, references, and highly technical passages may require manual handling."
So if your paper has footnotes, tables and a reference list, import one real chapter before the deadline and look at what you'd have to put back by hand. For a long document, its guide suggests breaking it into sections that fit your plan's per-output limit.
HumanPen starts from the file and stays in it. You upload the .docx (or .pptx, or .txt) and choose the whole document, passages you pick, or the ones a Turnitin or iThenticate report flagged. It rewrites inside the file, designed to keep citations, footnotes, tables and styles, and returns an editable file of the same type. If a recheck still flags something, bring the new report. Eligible passages can be re-run at no charge.
FAQ
Can I upload a Word file to GPTHuman?
Yes, after you log in. Its help center lists .docx and .pdf under Import from file; the text is extracted, and the result appears as text for you to copy. HumanPen takes a .docx or .pptx and returns the file itself, rewritten inside and still editable. It doesn't rewrite PDFs.
How much does GPTHuman cost?
On 11 September 2026, billed monthly: Starter $15, Plus $25 and Unlimited $49 a month, for 25,000, 60,000 and unlimited words a month (Unlimited is "subject to abuse guardrails"). The pricing page opens on annual billing, where the same plans show $8.25, $14 and $26 a month ($99, $168 and $312 a year); the "starting at $8.25/month" in its help center is that annual rate. Its pages say different things on some details: the help center gives Plus 100,000 credits a month, and the free trial is described as 300 words, 300 credits, or a 7-day trial in its terms. Go by what your account shows. Its terms say "All purchases are non-refundable." HumanPen sells credits charged on the words actually rewritten, and they don't expire; GPTHuman's web plans give a word allowance per billing cycle.
Both have an API and an MCP server. How do they compare?
GPTHuman's docs are readable without an account: POST /v1/humanize with a bearer key, taking 250 characters to 2,500 words of text per call, an MCP server on npm (@gpthuman/mcp-server, Node.js 22 or later) and a hosted MCP endpoint. Its pages say different things about API billing: the docs count credits on the words you send, the API page on the words generated. Go by what your account shows. HumanPen has a REST API, an MCP server and a Skill, all on the same credit balance.
Which one is more effective at lowering AI scores?
We haven't tested the two side by side, so we don't have a number to give you. The most reliable comparison is to run your own file through each one.
Compare the results on your own document
Use your signup credits to try a small selection of paragraphs. Upload a copy, then compare the returned file with the original.
Try it on your document