About GPTZero

Deep-learning detector that flags portions of text likely generated by AI versus human, classifying content as entirely human, AI, or mixed.

ai detectionclassification

GPTZero specs

Model ID: gptzero
Provider: GPTZero
Category: Tools & Agents
Input: text, document
Output: text
Endpoints: POST /v1/detect
POST /v1/chat/completions
POST /v1/responses
POST /v1/messages

GPTZero API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

Type

Spec

Rate

Text Scan

per 1,000 words

$0.39

Compare on the full pricing page

How to call the GPTZero API

GPTZero serves the OpenAI-compatible Chat Completions API. Point any OpenAI SDK at https://api.empiriolabs.ai/v1 with your EmpirioLabs API key and use the model id gptzero. Get an API key from the EmpirioLabs dashboard.

cURL

curl https://api.empiriolabs.ai/v1/chat/completions \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gptzero",
    "messages": [
      {"role": "user", "content": "Write a haiku about the ocean."}
    ]
  }'

Python (OpenAI SDK)

from openai import OpenAI

client = OpenAI(
    base_url="https://api.empiriolabs.ai/v1",
    api_key="YOUR_EMPIRIOLABS_API_KEY",
)

response = client.chat.completions.create(
    model="gptzero",
    messages=[{"role": "user", "content": "Write a haiku about the ocean."}],
)
print(response.choices[0].message.content)

Full GPTZero API reference

GPTZero API parameters

Request parameters supported by the GPTZero API on EmpirioLabs. Defaults apply when a field is omitted.

Parameter	Type	Default	Range / values	Description
input	string	-	-	Text to analyze
scan_type	enum	ai_detection	ai_detection, bibliography, sources, fact_check	AI Detection: detect AI-generated text. Bibliography: analyze citations and references. Sources / Fact Check: find supporting sources for claims in your text.
model_version	string	__latest__	-	Select a specific GPTZero model version, or leave as __latest__ for the newest rolling release. Choosing an explicit multilingual release overrides the separate...
file_url	string	-	-	URL of a document to scan instead of pasting text. Supported: PDF, DOC, DOCX, RTF, ODT, TXT, MD (max 25 MB). The worker downloads the file and forwards it to...
version	string	__latest__	-	Canonical name for model_version. Pin a specific upstream snapshot, or leave as __latest__ for the default rolling alias.
multilingual	boolean	false	-	Use GPTZero's multilingual detection path. Applies to text scans when Model Version is __latest__; file scans use whichever model version is selected.
ai_threshold	number	0.7	0.1 to 0.99	Probability cutoff for flagging sentences as AI-generated. Lower = more sensitive. Range 0.10 to 0.99.
max_sentences	number	15	1 to 50	Maximum number of sentences shown in the per-sentence breakdown section.
source_sentence	string	-	-	Optional. The exact sentence or claim you want to find supporting sources for. If left blank, the full input text is used as the claim. (sources / fact_check scan only.)
max_sources	number	3	1 to 10	Maximum number of sources to retrieve for each identified claim. (sources / fact_check scan only.)
confidence_threshold	number	0.5	0 to 1	Minimum confidence required for a source-match to be returned. Range 0 to 1. (sources / fact_check scan only.)
claim_extractor	string	claimbuster	-	Method used to extract claims from your text. claimbuster is faster; llm_claim_extractor is more thorough. (sources / fact_check scan only.)
disable_formatting	boolean	false	-	Skip the EmpirioLabs Markdown report (per-sentence highlights / scan summary / sources list). The raw upstream GPTZero JSON response is returned.

Good to know

File limits

Max 50 files per request
Combined size cap: 15 MB
Each document truncated to 50,000 characters

Supported formats

PDF, DOC, DOCX, TXT, ODT

GPTZero API: common questions

How much does the GPTZero API cost?

On EmpirioLabs, GPTZero is billed pay as you go: Text Scan $0.39 per 1,000 words. The live rate card on this page always matches what the API charges.

Is the GPTZero API OpenAI-compatible?

Yes. GPTZero serves the OpenAI-compatible Chat Completions API, so existing OpenAI SDKs work by pointing base_url at https://api.empiriolabs.ai/v1 and setting the model id to gptzero.

Can I try GPTZero in the browser before integrating?

Yes. The EmpirioLabs playground runs GPTZero in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a GPTZero API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.

GPTZero API