GPTZero vs Originality.AI

GPTZero

One of the detectors schools most often adopt, and the sentence-level highlighting is what makes a result usable in a conversation with a student rather than a bare percentage. No detector is evidence of authorship, though, and the cheap Essential tier is gone from the pricing page, so paid use now starts at Premium.

Pros

• +Sentence-level highlighting shows what drove the score instead of a bare percentage
• +Batch uploads and a developer API make it usable inside an existing review workflow
• +Free tier is generous enough to evaluate properly before paying

Cons

• −The Essential tier has been dropped, so the cheapest paid plan is Premium at $12.99 a month on annual billing or $23.99 month to month
• −The developer API is priced separately from the writing plans, starting at $45 a month
• −Word-metered quotas punish long documents disproportionately
• −Detection accuracy remains contested and the tool cannot prove authorship

Originality.AI

The detector to pick if you are a publisher or agency policing freelance output at volume, because the team history and writing replay matter more than the raw score. A free Basic tier (three AI-only scans a day, 2,000 words each) now lets you test it before paying. Do not use it to accuse a student; no detector is accurate enough to carry that weight.

Pros

• +Credit model is legible: 100 words per credit, no hidden weighting
• +API on the higher tier makes batch pipelines possible
• +Chrome extension works inside Google Docs, where the writing actually happens
• +Writing replay from revision history is process evidence, not just a score
• +Free Basic tier allows three AI-only scans a day with file upload, no subscription needed

Cons

• −Monthly subscription credits expire, so a light month is wasted spend
• −The jump from $14.95 to $179 a month is a steep single step
• −False positives on heavily edited or non-native English writing are a documented hazard across every detector
• −Accuracy benchmarks are largely vendor-run

Is GPTZero cheaper than Originality.AI?

On published entry prices, GPTZero starts lower — $12.99/mo against $14.95/mo for Originality.AI. Entry price is the lowest paid plan as we last verified it; what each plan includes differs.

Does GPTZero or Originality.AI have a free tier?

Both: GPTZero has a free tier, and Originality.AI has a free tier.

Which has a public API, GPTZero or Originality.AI?

Both ship a public API, so either can be built on; the fact table above shows the platforms each one runs on.