HumanPen vs Verva (formerly TwainGPT): one document, or a suite of writing tools
Verva takes pasted text or an uploaded .docx and puts an AI detector and a Chrome extension in the same account. HumanPen takes a .docx or .pptx, rewrites inside it, and hands the file back.
Competitor details verified 2026-09-11. Their own site is the authority.
The short answer
Verva is an all-round rewriting account: a humanizer, an AI detector, a writing generator and a Chrome extension on one subscription, in 100+ languages. It suits you if you rewrite in the browser, want to check your own text for AI, or write in more than one language. HumanPen does a narrower job: it rewrites an English .docx or .pptx inside the file, following your Turnitin or iThenticate report if you have one, and gives the file back.
Side by side
| HumanPen | Verva | |
|---|---|---|
| Input | Upload the document itself | Paste text, or upload .txt, .md, .rtf, .csv, .json or .docx (.pptx is not in the upload list) |
| Output | The same file back, still editable | Not stated on its pages; the visible editor shows an output box, and results are saved to a Documents page in your account |
| Per-request word cap | None | The editor counter shows 2,000 words (logged out); per-plan caps not stated |
| 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 |
| Billing | Metered credits, never expire | Monthly or annual subscription, metered in words per month (Free 250 / Basic 8,000 / Premium 30,000 / Ultimate unlimited) |
| Adjacent tools | Citation fix, condense, translate | AI detector, writing generator, Chrome extension |
| Agent / API integration | Skill, MCP, and REST API — callable from AI agents | No API found on its public pages |
| Rewrite languages | English only | 100+ |
When to pick Verva
- You want to check for AI where you rewrite. Verva has its own detector, with a sentence-level Advanced Scan on paid plans. HumanPen has none: you bring a Turnitin or iThenticate report, or pick the passages yourself.
- You write in a language other than English. Verva lists 100+ languages; HumanPen only works in English.
- You rewrite as you go in the browser. Verva's Chrome extension draws on the same word allowance as your account.
- Your texts are short and a flat monthly price suits you. Basic is $10 a month billed monthly ($96 a year billed annually) for 8,000 words a month.
Both take a .docx. The difference is what comes back.
Verva's upload box takes .docx (not .pptx), so you can start from a file with either tool. On Verva's pages the result appears in an output box and is saved to a Documents page in your account; they don't mention downloading a file or keeping formatting. If you plan to use it on a paper, run one file with footnotes, a table and a reference list through it first and see what you get.
HumanPen rewrites inside the .docx or .pptx and returns an editable file of the same type, designed to keep citations, footnotes, tables and styles in place. You can rewrite the whole document, passages you pick, or only 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.
Billing works differently too. Verva's word allowance resets every month, on annual plans as well. HumanPen charges credits for the words actually rewritten, and they don't expire. If your writing comes in bursts (a chapter in March, nothing until June), that matters more than the monthly price.
FAQ
Is Verva the same as TwainGPT?
Yes. TwainGPT is Verva's old name, and twaingpt.com now redirects to verva.com. Everything on this page describes Verva's current plans and features.
Verva accepts .docx too. What is the difference?
Mainly what you get back. HumanPen returns the same .docx or .pptx, rewritten inside and still editable. Verva's pages show an output box, with results saved to your Documents page. The quickest way to decide is to run one real chapter through both and open what comes back.
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.
Is Verva the same company as Undetectable.ai?
They're easy to mix up, but no. undetectable.com is another Verva, LLC brand: its footer carries a Verva, LLC copyright and its upload box takes the same file types. Undetectable.ai is a separate site, run by Undetectable Inc. as of our August check, and our Undetectable.ai comparison is about that 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