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GPTinf vs Undetectable AI

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Undetectable AI publishes a starting price ($9.99); GPTinf does not. Both have a free tier. Only Undetectable AI ships a public API.

GPTinfRewrites AI-generated text to read as human-writtenUndetectable AIRewrites machine-written drafts to read human, with detection scoring built in

Side by side

FactGPTinfUndetectable AI
CategoryAI Detection & HumanizersAI Detection & Humanizers
Pricing modelFreemiumFreemium
Starts at—$9.99 month
Public APINoYes
PlatformsWebWeb, API, Chrome Ext
Company—Undetectable Inc.
Launched—2023
Last verifiedSep 6, 2026Sep 6, 2026

What our research says

GPTinf

This is a detector-evasion rewriter and you should judge it as exactly that. If you are a student, running coursework through it is an academic-integrity violation whether or not the detector catches you.

Pros

  • word locking preserves citations, proper nouns and product names through the rewrite
  • a usable trial runs without an account, so you can judge output before paying
  • priced by word volume rather than per seat, which suits occasional use
  • one screen, no setup, no onboarding

Cons

  • independent reviews rate output as inconsistent, particularly across longer paragraphs
  • detector evasion is an arms race, so what passes this month can fail next month
  • no company name, team or jurisdiction disclosed anywhere on the site
  • no API, so it cannot be wired into a content pipeline

Undetectable AI

Buy it only if you accept that passing a detector is a moving target: detector vendors retrain constantly, and text that cleared last month can flag next month. As a multi-format detection dashboard it is more defensible than as a bypass tool.

Pros

  • Detector and rewriter run in one pass, so you see which sentences changed and why
  • Coverage extends past text into image, voice, video and document classifiers
  • Browser extension works inside Docs and Gmail rather than a separate tab
  • Entry tier is genuinely cheap at annual rates

Cons

  • Rewrites often flatten voice and add filler to break statistical patterns
  • Detection on short passages is unreliable in both directions
  • Word quotas drain fast because rejected attempts still consume them
  • The free trial caps at 250 words, barely enough to judge output quality

Which one fits

Choose GPTinf if you need

  • marketers loosening obviously templated AI copy before a human edit pass
  • stress-testing how brittle your own organisation's AI-detection policy is
  • writers who want a paraphrase pass with specific terms locked in place

Choose Undetectable AI if you need

  • Marketers cleaning up bulk LLM drafts before publishing
  • Editors wanting a second opinion on submitted copy
  • Teams screening images and audio for synthetic origin
  • Non-native writers smoothing register and tone

More comparisons

All GPTinf alternatives →All Undetectable AI alternatives →Browse all AI Detection & Humanizers →