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ProofWrite 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. Both start at $9.99. Both have a free tier. Only Undetectable AI ships a public API.

ProofWriteRewrites AI-generated text to read more naturally and pass detectors like Turnitin, GPTZero, and Originality.ai.Undetectable AIRewrites machine-written drafts to read human, with detection scoring built in

Side by side

FactProofWriteUndetectable AI
CategoryAI Detection & HumanizersAI Detection & Humanizers
Pricing modelFreemiumFreemium
Starts at$9.99 month$9.99 month
Public APINoYes
PlatformsWebWeb, API, Chrome Ext
Company—Undetectable Inc.
Launched—2023
Last verifiedSep 1, 2026Sep 6, 2026

What our research says

ProofWrite

ProofWrite is built around one specific job: getting AI-written text past detection tools while keeping the meaning intact, verified against a stated list of detectors rather than a vague claim. The catch is that detector behavior changes over time, so passing today's check doesn't guarantee it holds up against a future detector update, and 250 free words isn't much to evaluate quality on your own text.

Pros

  • checks output against seven named detectors rather than just one
  • eight writing modes for different tones, including academic, formal, and blog
  • free tier and no-card signup to test before paying

Cons

  • detector-passing behavior can change whenever those detectors update their models
  • only 250 free words to evaluate before hitting a paywall
  • unlimited-word tier requires the top Ultra plan

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 ProofWrite if you need

  • students and academics needing text that reads naturally
  • SEO writers and content teams producing high volumes of AI-assisted copy
  • anyone needing output checked against multiple named detectors at once

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