You want one focused review-and-revise workflow
Penlify's free plan includes 3 detections and 5 rewrites a month in the same workspace — no upgrade required to act on a flagged sentence.
The short answer
Choose ZeroGPT if you want one broad toolkit for detection, plagiarism, grammar, and other writing utilities. Choose Penlify if you want a focused workspace for reviewing and revising your own draft.
You want one toolkit for many checks
Plagiarism, grammar, summarizing, translation, and image/video AI detection are bundled alongside its detector — useful if you want fewer tabs open for unrelated tasks.
Feature and workflow comparison
ZeroGPT's current pages show a free plan, a Basic Public Humanizer, and paid personal, business, and API offerings. Confirm plan-specific limits and prices before buying.
| Area | Penlify | ZeroGPT |
|---|---|---|
| Free access | 3 detections/month and 5 rewrites/month, no card required. | Free plan available; current plan limits should be checked on its pricing page. |
| Free rewriting | 5 rewrites/month included free. | Basic Public Humanizer is available; its Advanced model is offered through Undetectable AI. |
| Paid plans | $2.99/mo or $24.99/yr (~$2.08/mo), unlimited. | Personal, business, EDU, and API offerings; plan-specific prices and limits vary. |
| Revision workflow | Rewrite a flagged sentence in the same workspace. | Separate Humanizer tool alongside the detector. |
| Plagiarism checking | Not offered. | Included in its broader toolkit. |
| Other bundled tools | None — detection and rewriting only. | Grammar checker, summarizer, translator, dictionary, image and video AI detectors. |
| Built for | A writer checking and fixing their own draft. | Anyone wanting one broad, free AI-content toolkit. |
Honest tradeoff: ZeroGPT's toolkit covers more jobs than Penlify does, including plagiarism, grammar, summarizing, translation, and image/video checks. Penlify keeps the workflow narrower: review a draft, revise it, and make the final decision yourself.
Features checked against ZeroGPT's official pricing page and AI Humanizer page on 26 September 2026. Plan details can change.
Free access is not the same as one workflow
ZeroGPT's current site offers a free plan and a Basic Public Humanizer, along with a much larger collection of tools. That is useful when the job includes detection, plagiarism, grammar, summarizing, translation, or media checks.
The practical difference is workflow. ZeroGPT presents humanizing as a separate tool, and offers an Advanced model through Undetectable AI. A writer should review any result for facts, names, tone, and policy compliance before sending or submitting it.
Penlify built the free tier around that exact moment instead. Three detections and five rewrites a month cost nothing, so seeing which sentence is the problem and getting a rewritten version to review both happen without a card on file. The tradeoff is scope: Penlify doesn't check plagiarism, grammar, or translate anything. It's built to do one thing — detect and fix a writer's own draft — and give that away free.
What "sentence-level" actually looks like
This is an illustration of the workflow difference, not a live side-by-side run of both tools — always check a real detector's current output for that.
71% AI-generated
One number for the whole document. It doesn't say which sentence to fix.
"In today's fast-paced world, effective communication has become increasingly important." high AI-pattern
"Our team missed the first deadline, but shipped the fix two days after the second." reads as natural
Same paragraph, same underlying signal — the difference is whether you get a verdict or a map of what to rewrite.
Common questions
Does ZeroGPT have free rewriting?
ZeroGPT's current Humanizer page provides a Basic Public Humanizer. Its Advanced model is presented as an option from Undetectable AI. Penlify's free plan includes 3 detections and 5 rewrites a month, no card required.
Does ZeroGPT check plagiarism too?
Yes. ZeroGPT bundles a plagiarism checker, grammar checker, summarizer, translator, and image/video AI detection alongside its core AI detector. Penlify does not check plagiarism — it focuses on AI-pattern detection and rewriting a writer's own draft.
How does ZeroGPT pricing compare to Penlify?
ZeroGPT has a free plan and paid personal, business, and API offerings. Its pricing interface can change by plan and billing period, so confirm the current price directly before subscribing. Penlify's paid plan is $2.99 a month or $24.99 a year for unlimited detection and rewriting.
Test the workflow with your own draft
Start with the private analyzer. It gives value without requiring an account or sending the text to Penlify.