Side-by-side comparison · Writing & Translation
GPTZero vs Originality.ai vs Undetectable AI
Everything that matters when choosing between them, in one place: our rating, what each can do, what they cost, and the trade-offs.
Comparing 3 tools, the maximum.
At a glance
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: Marketers and writers who use AI for first drafts and want them to sound less robotic.
Overview
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| In one line | Checks 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. | Rewrites AI-written text so it reads more human and is less likely to get flagged. |
| Pricing model | Freemium | Freemium | Freemium |
| Starting price | $0 | $14.95/mo | $0 |
| Free plan | Yes | Yes | Yes |
| Works with Claude Code | Yes | Yes | Yes |
Rating breakdown
Our scores out of 5. The higher bar in each row is highlighted.
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Overall rating | 4.2Winner | 4.1 | 3.6 |
| Ease of useHow quickly someone non-technical gets value from it. | 4.5 | 4.0 | 4.0 |
| FeaturesHow completely it covers its own job, and how well the pieces fit together. | 4.5 | 4.5 | 3.5 |
| Output qualityHow good the results are before you fix them. | 3.5 | 3.5 | 3.0 |
| Value for moneyWhat you get for the price, including the free plan. | 4.0 | 4.0 | 3.5 |
| Speed & reliabilityHow fast it is and how often it falls over. | 4.5 | 4.5 | 4.0 |
Feature comparison
A tick means it does this today. A dash means we haven't checked.
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Access & platform | |||
| Free plan | Yes | Yes | Yes |
| Mobile app | No | – | No |
| Desktop app | – | – | – |
| Browser extension | Yes | Yes | Yes |
| API access | Yes | Yes | Yes |
| Teams & business | |||
| Team workspace | Yes | Yes | No |
| Enterprise plan or SSO | Yes | Yes | – |
| Connects to other apps | Yes | Yes | No |
| Open source or self-hosted | No | No | No |
| AI abilities | |||
| Works with your files | Yes | Yes | Yes |
| Understands images | – | – | Yes |
| 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 | – | – | – |
| Works in many languages | Yes | – | Yes |
| Capabilities score | 8/ 17 | 7/ 17 | 6/ 17 |
Pricing
Plans as listed on each vendor's site when we last checked. Confirm before you buy.
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Plans | Free $0 Checking the odd document. | Free Free Checking the odd article. | Free $0 Testing one short piece. |
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. | 10K words $9.99/mo, or $5/mo billed yearly ($60) Occasional use. | |
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. | 20K wordsOur pick $19/mo, or $9.50/mo billed yearly ($114) Regular blog content. | |
Team Professional price per seat, 2 seats minimum Schools and businesses buying for a group. | Larger plans From $31/mo, or $15.75/mo billed yearly Agencies and high volume. | ||
| Which plan to pick | Start 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. | Test the free 250 words on your own writing first. If the output works for you, a small yearly plan is cheap. Word credits reset monthly, so don't buy more than you use. |
Key features
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Standout features |
|
|
|
Pros and cons
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Pros |
|
|
|
| Cons |
|
|
|
Who each one is for
| Attribute | GPTZero | Originality.ai | Undetectable AI |
|---|---|---|---|
| Best for |
|
|
|
| You'll find it used by |
|
|
|
Questions people ask
Which is better, GPTZero, Originality.ai or Undetectable AI?
GPTZero scores highest overall in our ratings (GPTZero 4.2/5, Originality.ai 4.1/5 and Undetectable AI 3.6/5). 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. Undetectable AI is best for Making AI drafts sound less robotic and seeing how detectors might score your text.
Which is cheaper, GPTZero, Originality.ai or Undetectable AI?
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. Undetectable AI: There's a free plan, and paid plans start at $0.
Which is easier to use, GPTZero, Originality.ai or Undetectable AI?
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.
Swap in another tool
More tools from Writing & Translation in the library.
