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Side-by-side comparison · Writing & Translation

GPTZero vs Originality.ai vs ProWritingAid

Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.

Best overall

GPTZero

4.2

From $0

Originality.ai

4.1

From $14.95/mo

ProWritingAid

3.9

From $0

Comparing 3 tools, the maximum.

At a glance

Best overallEasiest to use

Pick it if: Teachers, editors and business owners who want a second opinion on whether writing they've been handed came from AI.

Pick it if: Publishers, content agencies, SEO teams and businesses that commission written content and want to check it before publishing.

Pick it if: Authors, bloggers and anyone writing long documents who wants detailed feedback on style as well as typos.

Overview

AttributeGPTZeroOriginality.aiProWritingAid
In one lineChecks whether text was written by AI, with plagiarism and citation checks too.Checks content for AI writing, plagiarism and factual errors before you publish it.Grammar and style checker for authors, with in-depth reports on long manuscripts.
Pricing modelFreemiumFreemiumFreemium
Starting price$0$14.95/mo$0
Free plan Yes Yes Yes
Works with Claude Code Yes Yes No

Rating breakdown

Our scores out of 5. The higher bar in each row is highlighted.

AttributeGPTZeroOriginality.aiProWritingAid
Overall rating4.2Winner4.13.9
Ease of useHow quickly someone non-technical gets value from it.
4.5
4.0
3.5
FeaturesHow completely it covers its own job, and how well the pieces fit together.
4.5
4.5
4.5
Output qualityHow good the results are before you fix them.
3.5
3.5
4.0
Value for moneyWhat you get for the price, including the free plan.
4.0
4.0
4.0
Speed & reliabilityHow fast it is and how often it falls over.
4.5
4.5
3.5

Feature comparison

A tick means it does this today. A dash means we haven't checked.

AttributeGPTZeroOriginality.aiProWritingAid
Access & platform
Free plan Yes Yes Yes
Mobile app No– No
Desktop app–– Yes
Browser extension Yes Yes Yes
API access Yes Yes–
Teams & business
Team workspace Yes Yes No
Enterprise plan or SSO Yes Yes–
Connects to other apps Yes Yes Yes
Open source or self-hosted No No No
AI abilities
Works with your files Yes Yes Yes
Understands images–––
Makes images No No No
Makes video No No No
Writes code No No No
Runs agents or automations No No No
Learns your brand or style–– Yes
Works in many languages Yes––
Capabilities score8/ 177/ 176/ 17

Pricing

Plans as listed on each vendor's site when we last checked. Confirm before you buy.

AttributeGPTZeroOriginality.aiProWritingAid
Plans

Free

$0

Checking the odd document.

Free

Free

Checking the odd article.

Free

$0

Trying the reports on short pieces.

PremiumOur pick

$23.99/mo, or $12.99/mo billed yearly

Teachers and editors checking work every week.

ProOur pick

$14.95/mo, or $12.95/mo billed yearly

Agencies and site owners checking content every week.

PremiumOur pick

$30/mo, or $10/mo billed yearly ($120)

Writers editing regularly.

Professional

$45.99/mo, or $24.99/mo billed yearly

Agencies and heavy users scanning lots of files.

Enterprise

$179/mo, or $136.58/mo billed yearly

Publishers and large content teams.

Premium Pro

$36/mo, or $12/mo billed yearly ($144)

Authors who want feedback and a community.

Team

Professional price per seat, 2 seats minimum

Schools and businesses buying for a group.

Which plan to pickStart on Free. If you check more than a few documents a week, Premium on yearly billing is the sweet spot. Professional only makes sense if you scan big batches of files.Pro is enough for most agencies and site owners. An AI and plagiarism check together uses two credits per 100 words, so budget about 100,000 words of checked content a month. Go Enterprise only if you need the API or very high volume.Try Free on a chapter or a long blog post. If it clicks, Premium on yearly billing is good value, and the lifetime deal pays off after about three years. Premium Pro is for authors who want daily critiques and the workshops.

Key features

AttributeGPTZeroOriginality.aiProWritingAid
Standout features
  • AI detection
  • Plagiarism check
  • Writing replay
  • Citation and hallucination check
  • Batch scans
  • API and school integrations
  • AI detection
  • Plagiarism checker
  • Fact checker
  • Bulk and site scans
  • Writing replay
  • API
  • Grammar and spelling
  • 25+ writing reports
  • Chapter Critique
  • Rephrase and Sparks
  • Story Canvas and Outline Crafter
  • Works where you write

Pros and cons

AttributeGPTZeroOriginality.aiProWritingAid
Pros
  • Clear sentence-level highlights, so you see exactly what looks AI-written
  • Generous free plan for occasional checks
  • Writing replay gives honest writers a way to prove their work
  • Flags made-up citations, which most detectors don't
  • API and batch scans for larger volumes
  • AI, plagiarism, facts and readability in one scan
  • Cheap for the volume on Pro
  • Bulk and whole-site scanning
  • Writing replay gives honest writers a way to prove their work
  • API for content teams
  • The most detailed style reports of any writing checker
  • Explains its suggestions, so you improve over time
  • Lifetime plan means no ongoing subscription
  • Works in Word, Google Docs and Scrivener
  • AI feedback built for fiction writers
Cons
  • False positives happen, and short or formal writing gets flagged more often
  • Edited or reworded AI text can get past it
  • The best scan and plagiarism checks need a paid plan
  • Mostly designed around schools, so some features won't matter to a business
  • False positives are a recurring complaint, and independent tests find more than the vendor claims
  • Monthly credits expire if you don't use them
  • API is only on the expensive Enterprise plan
  • A score can sour a client or writer relationship if treated as proof
  • So many reports that it takes time to learn
  • Monthly billing is expensive next to yearly
  • Free plan is limited to 500 words per check
  • Can feel slow on very long documents
  • Overkill for quick business emails

Who each one is for

AttributeGPTZeroOriginality.aiProWritingAid
Best for
  • Checking essays and assignments for AI writing
  • Screening freelance or agency content
  • Spotting made-up citations in reports
  • Showing you wrote a document yourself
  • Checking freelance and agency content
  • AI and plagiarism checks in one scan
  • Fact-checking articles before they go live
  • Bulk scanning a website
  • Proving a writer wrote their own draft
  • Editing a novel or long manuscript
  • Finding repeated words and clunky sentences
  • Learning to write better as you edit
  • Editing inside Word, Google Docs or Scrivener
You'll find it used by
  • Teachers
  • Editors
  • Content agencies
  • Recruiters
  • Students
  • Content agencies
  • Publishers
  • SEO teams
  • Marketing managers
  • Website buyers
  • Novelists
  • Bloggers
  • Non-fiction authors
  • Students
  • Editors

Questions people ask

Which is better, GPTZero, Originality.ai or ProWritingAid?

GPTZero scores highest overall in our ratings (GPTZero 4.2/5, Originality.ai 4.1/5 and ProWritingAid 3.9/5). GPTZero is best for checking essays and assignments for AI writing and screening freelance or agency content. Originality.ai is best for checking freelance and agency content and AI and plagiarism checks in one scan. ProWritingAid is best for editing a novel or long manuscript and finding repeated words and clunky sentences.

Which is cheaper, GPTZero, Originality.ai or ProWritingAid?

GPTZero: There's a free plan, and paid plans start at $0. Originality.ai: There's a free plan, and paid plans start at $14.95/mo. ProWritingAid: There's a free plan, and paid plans start at $0.

Which is easier to use, GPTZero, Originality.ai or ProWritingAid?

GPTZero rates highest for ease of use in our scores. Teachers, editors and business owners who want a second opinion on whether writing they've been handed came from AI.

How we compare

Ratings are our own, from using each tool, across ease of use, features, output quality, value for money, speed & reliability.

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