Enter API details on the right to test your key
Powered by APIMaster.AI exclusive LLM fingerprinting
True fingerprinting · Verify before you trust
Total Detections
0
Fake Model Rate
0%
Most Detected
—
Test OpenAI, Claude, Gemini & DeepSeek API keys instantly. Verify connectivity, check key validity, and detect model authenticity — free AI API testing tools.
Buy OpenAI, Claude, Gemini & DeepSeek API keys in one click — save 90% on OpenAI · 85% on Claude · 15% on DeepSeek. Fingerprint-verified, best channels, one stop.
Three steps to detect fake LLM models and verify API authenticity
We collect large volumes of model responses using hundreds of prompts and noise patterns to build a fingerprint database — the foundation for identifying fake or substituted models.
Based on behavior rather than self-reported identity, we extract fingerprint features from responses — like human fingerprints, these cannot be faked by relay proxies.
Probe questions verify whether you're getting the real Claude, GPT, or DeepSeek — or a cheaper fake substitute quietly swapped in by the API provider.
Real detection results — track which AI API providers serve genuine models vs. fake substitutes
| Rank | Site | Model | Score | Avg Latency | P95 Latency |
|---|---|---|---|---|---|
| No data yet | |||||
Shop fingerprint-verified providers. No model substitution, no fake APIs. OpenAI, Claude, DeepSeek and more — all checked before listing.
Many API proxies secretly swap expensive models for cheaper ones — you pay for Claude or GPT-4 but get a discount model in return. APIMaster.AI detects this through genuine LLM behavioral fingerprinting: trained on massive samples, it identifies the real model behind any API endpoint — not by asking questions the proxy can fake, but by analyzing deep behavioral signals that cannot be spoofed.