HumanPen vs ProofreaderPro: the whole document, or body text you paste back
ProofreaderPro's Humanizer asks for body text only and returns raw text for you to re-insert. HumanPen processes the whole .docx or .pptx and returns the file.
Competitor details verified 2026-09-11. Their own site is the authority.
The short answer
ProofreaderPro is a proofreading suite for academic writing, and its Humanizer is built for body text: you paste paragraphs in, get plain text back, and put it into your paper yourself. That works well when you only need a few paragraphs reworked, write in another language, or want the changes as Word tracked changes. HumanPen handles the whole English .docx or .pptx and returns the file.
Side by side
| HumanPen | ProofreaderPro | |
|---|---|---|
| Input | Upload the document itself | Paste text; paid plans can upload TXT, DOC or PDF (its homepage says .docx, .pdf or .txt) |
| Output | The same file back, still editable | Text. The Humanizer FAQ says "output as raw text" and recommends pasting body text only. Export TXT / DOC (PDF on Academic Plus), or a .docx with Word tracked changes (tracked-change export listed on Academic Plus) |
| Per-request word cap | None | Humanizer: 500 words (Academic) / 1,000 (Academic Plus); Free plan editing 250; API 50–1,000 |
| 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; no target word-range setting seen |
| Billing | Metered credits, never expire | Monthly or annual subscription counted in words; top-up packs never expire; the API is sold separately as word packs valid for 12 months |
| Adjacent tools | Citation fix, condense, translate | AI proofreader, paraphraser, summarizer, translator, plus free tools (grammar checker, citation generator and others); no standalone AI detector or plagiarism checker on its pages |
| Agent / API integration | Skill, MCP, and REST API — callable from AI agents | Humanizer REST API, granted per project on request; MCP / Skill not stated |
| Rewrite languages | English only | 60+ (the multilingual Humanizer is on Academic Plus) |
When to pick ProofreaderPro
- You want proofreading, paraphrasing, summarizing and translation in one account. The Humanizer is one tool in that suite; HumanPen doesn't proofread or summarize.
- You only need a few body paragraphs rewritten. If you'd be pasting paragraphs anyway, its Humanizer is designed for exactly that, and 500 or 1,000 words per pass covers it.
- You want to review every change as a Word tracked change. Its Humanizer can download a .docx with each insertion and deletion as a native tracked change (exporting tracked changes is listed on Academic Plus).
- You write in a language other than English. The Academic Plus Humanizer covers 60+ languages; HumanPen only works in English.
- You want a free plan with no time limit. Its Free plan gives 250 words a month for the editor.
Body text in, raw text out
ProofreaderPro is upfront about this. Its FAQ says the model was trained on body text, recommends pasting body paragraphs only (no headings, titles, captions or formulas), and adds: "Whatever you input will be processed and output as raw text. So it is best to humanize your body text first, and then re-insert it into your structured paper."
For a few paragraphs that's quick. On a long paper it means copying each section out, running it in 500- or 1,000-word passes, and pasting the results back between your headings, captions and citations.
HumanPen starts from the file instead. You upload the .docx or .pptx and it rewrites inside it, designed to keep citations, footnotes, tables and styles in place, then returns an editable file of the same type. You can limit it to what a Turnitin or iThenticate report flagged. If a recheck still flags something, bring the new report. Eligible passages can be re-run at no charge.
FAQ
Can I upload my whole paper to ProofreaderPro's Humanizer?
You can upload TXT, DOC or PDF on a paid plan, but its own FAQ recommends pasting body text only, and the output is raw text that you put back into your paper. HumanPen takes the whole .docx or .pptx and returns the file; it doesn't rewrite PDFs.
Is ProofreaderPro's Humanizer free?
Its pages say different things. The Humanizer page offers 250 free words a month, and its free-tools page lists the Humanizer as free with an account. Its terms and main FAQ call it a paid feature, and the Free card on its pricing page doesn't list it. Go by what your account shows before you pay. HumanPen gives new accounts 100 credits (1,000 words) once.
Does ProofreaderPro have an AI detector?
Its public pages don't list a standalone detector. Each run shows a Human Score, which it describes as a per-doc heuristic estimating how AI detectors would read the text; that's its own estimate, not a detector report. HumanPen has no detector and gives no score. To rewrite only flagged passages, you bring a Turnitin or iThenticate report.
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