Best Free GPTZero Alternatives
20 alternatives to GPTZero with a free plan or free tier, ranked by how closely they match. The percentage is a match score, not a popularity score.
Replacing: GPTZero — Used by over 10 million teachers and students across more than 100 countries, GPTZero deteInput: text, documents · Output: text, data
1
Developers get API access for building AI detection into their own apps
Developer-friendly detector with API access for embedding in your own apps; plagiarism checks too
Input: text, documents, web pages · Output: text, data
Free planFrom $12.95/mo
88%Strong alternative · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
2
Winston AI is an AI content detector and plagiarism checker built for education, SEO, and writing.
Built for education, SEO and writing; detector plus plagiarism checker with team features and API
Input: text, images, documents · Output: data
Free planFrom $10/moAPITeams
82%Strong alternative · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
3
Dechecker AI breaks down AI detection differently
Breaks AI detection results down differently, with a humanizer add-on; from $5 monthly
Input: text, documents · Output: text
Free planFrom $5/mo
72%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Humanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
4
The free plan hands you 5,000 characters per check
Free plan allows 5,000 characters per check; paid from $7 monthly
Input: text, documents · Output: text
Free planFrom $7/mo
70%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
5
ZeroGPT Plus can detect if text came from AI with high accuracy
Detector with humanizer and plagiarism tools bundled in; free tier available
Input: text, documents · Output: text
Free planFrom $9.9/mo
70%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Humanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
6
Detect.ai combines an AI content detector with a humanizer in a single browser tool.
Detector and humanizer together in one browser tool, with a mobile app; free tier
Input: text, documents · Output: text
Free planFrom $15.99/moMobile app
62%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
Score set by our editors after reviewing both products; the overlap below is what they weighed.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Also tagged for
Humanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
7
Rephrase until it sounds right
Input: text, images, documents · Output: text, images, documents, slides
Free planFrom $19.95/mo
60%Partial replacement — covers the main need with gaps
00
How the score adds up
- One lists the other's core category30/55
- Covers GPTZero's goals19/25
- Feature description similarity11/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Grammar CheckingRewritingSummarizingWritingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
8
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity3/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
9
OmniDetect is an AI content detector that focuses on what to fix before you submit a piece of writing.
Input: text, documents, web pages · Output: text, data
Free planFrom $9.99/mo
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity5/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
10
Sapling AI Detector scores pasted text or uploaded PDF and Word files for the probability that a model wrote it.
Input: text, documents · Output: data
Free planFrom $12/moAPIBrowser extensionTeams
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity7/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
11
Pangram Labs makes an AI detector that checks whether text was written by a person or generated by a language model.
Input: text, images, documents · Output: data
Free planFrom $20/moAPIBrowser extension
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals25/25
- Feature description similarity13/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
12
isFake.ai is a tool designed for detecting AI-generated content across different media types, including text, images, audio, and videos. It employs proprietary algorithms to analyze for characteristic
Input: text, images, audio, video · Output: data
Free planFrom $3.99/mo
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity8/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
13
Scribbr AI Detector is a free checker that estimates whether a piece of writing was produced by an AI model.
Input: text · Output: data
Free plan
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals25/25
- Feature description similarity8/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Humanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
14
Scribbr Plagiarism Checker compares a document with a database of 99 billion web pages and 8 million publications and shows where the text matches existing sources.
Input: text, documents · Output: documents
Free plan
61%Partial replacement — covers the main need with gaps
00
How the score adds up
- Each lists the other's core category39/55
- Covers GPTZero's goals19/25
- Feature description similarity6/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Grammar Checking
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
15
AI or Not is an AI detector that checks whether images, text, video, audio and music were generated by AI, and flags deepfakes.
Input: text, images, audio, video · Output: data
Free planFrom $5/moAPITeams
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity10/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
16
Reality Defender detects deepfakes and AI-manipulated media across audio, video and images.
Input: images, audio, video · Output: data
Free planAPITeams
61%Partial replacement — covers the main need with gaps · same core category as GPTZero
00
How the score adds up
- Same core category55/55
- Covers GPTZero's goals16/25
- Feature description similarity6/20
Capped below the editor-ranked picks above it.
Shared goals 1 of the 2 we tag GPTZero for
AI Detection
Also tagged for
Fake Image Detection
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
17
Writing confidence that follows you everywhere
Input: text · Output: text
Free planFrom $12/mo
56%Limited overlap
00
How the score adds up
- One lists the other's core category30/55
- Covers GPTZero's goals19/25
- Feature description similarity7/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Grammar CheckingRewritingWritingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
18
56%Limited overlap
00
How the score adds up
- One lists the other's core category30/55
- Covers GPTZero's goals19/25
- Feature description similarity7/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Essay WritingGrammar CheckingRewritingWritingHumanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
19
Trinka is an AI writing assistant and grammar checker aimed at academic and technical writing.
Input: text, documents · Output: text, documents
Free planTeams
58%Limited overlap
00
How the score adds up
- One lists the other's core category30/55
- Covers GPTZero's goals19/25
- Feature description similarity9/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Grammar CheckingRewritingWriting
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
20
A content marketer drafts 15 blog posts using AI, then realizes every piece sounds robotic and formulaic
Input: text · Output: text
Free planFrom $7.99/mo
53%Limited overlap
00
How the score adds up
- One lists the other's core category30/55
- Covers GPTZero's goals19/25
- Feature description similarity4/20
Capped below the editor-ranked picks above it.
Shared goals 2 of the 2 we tag GPTZero for
AI DetectionPlagiarism Checking
Also tagged for
Humanizing Text
Goal tags are curated and capped, not a full feature audit — a missing tag is not a missing feature.
Can it really replace GPTZero? Vote on each alternative — no account needed. Votes gently reorder the list; they never change the match score.
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At a glance: top GPTZero alternatives
| Tool | Match | Input | Output | Pricing | Free plan | Rating | Category |
|---|---|---|---|---|---|---|---|
| Originality.AI | 88% | text, documents, web pages | text, data | From $12.95/mo | Yes | — | AI Detector |
| Winston AI | 82% | text, images, documents | data | From $10/mo | Yes | — | AI Detector |
| Dechecker AI | 72% | text, documents | text | From $5/mo | Yes | — | AI Detector |
| Detecting-AI.com | 70% | text, documents | text | From $7/mo | Yes | — | AI Detector |
| ZeroGPT Plus | 70% | text, documents | text | From $9.9/mo | Yes | — | AI Detector |
| Detect.ai | 62% | text, documents | text | From $15.99/mo | Yes | — | AI Detector |
Frequently asked
What is the best free GPTZero alternative?
Originality.AI (88% match) is the closest free alternative to GPTZero. Winston AI (82% match) and Dechecker AI (72% match) come next.
What is the best GPTZero alternative for checking for plagiarism?
Originality.AI ranks first for checking for plagiarism at 82% match. See the full list of GPTZero alternatives for Plagiarism Checking.
How is the match percentage calculated?
It measures how much of GPTZero's job a tool can take over: shared core category, how many of the same use cases it covers and how similar its feature set is. Popularity and ratings never change the percentage; they only break ties in the order. Lists are recomputed nightly and reviewed by editors for the most-visited tools.
How this list is ranked
The match score measures how much of GPTZero's job each tool can take over: shared core category, how many of the same use cases it covers, and how similar its feature set is. Popularity and ratings do not change the score; they only break ties in the order.
Lists are recomputed nightly from the live catalog and reviewed by our editors for the most-visited tools. Sponsored placements are marked and sit outside the ranking.