An API key checker is a free online tool that lets you instantly validate whether an AI API key is active, expired, or invalid — without writing a single line of code. Simply paste your key and get immediate feedback on its status.

Whether you're working with OpenAI API keys, Anthropic Claude keys, Google Gemini keys, or other AI provider tokens, this tool checks your key against the provider's authentication endpoint in real time.

Why validate your API key?

Quickly diagnose API authentication errors (401 Unauthorized) before debugging your application
Verify key permissions and quota limits without running your full stack
Check if a leaked or rotated key is still active
Onboard new team members by confirming their keys work before development begins
Test keys from CI/CD pipelines or staging environments instantly

How to check an API key online

Paste your key into the input field above and click Check. The tool sends a minimal authenticated request to the provider's API and reports the result — valid, invalid, or quota exceeded — in under a second. No server stores your key; all requests go directly from your browser.

Frequently asked questions

Is my API key stored or logged?

No. The validation request is made directly from your browser. Your key is never sent to or stored on gettinytool.com servers.

Which AI providers are supported?

OpenAI (GPT-4, GPT-3.5), Anthropic (Claude), Google (Gemini), Mistral, Cohere, and more — the list is regularly updated.

What does "quota exceeded" mean?

Your key is valid but you've hit the rate limit or billing cap set by the provider. Top up your account or wait for the limit to reset.