Idempotency Key Generator
Create keys for retryable API operations in your browser. Generation uses Web Crypto locally; this tool never sends a request or manages idempotency.
A QUICK WALKTHROUGH
How to use this tool
- Choose UUID v4 or UUID v7, an optional 1–32 character prefix, and a batch size.
- Generate keys locally and copy the HTTP, cURL, or JavaScript fetch example for your endpoint.
- Download the newline-separated TXT or CSV batch when you need to keep the output. Reuse the same key when retrying one logical operation; create a new key for a new operation.
For idempotent API requests
Send one generated value as the Idempotency-Key header for one logical operation. If that operation is retried, reuse its original key; use a new key for a new operation. API requirements may impose a different format or prefix.
Local UUID generation
UUID v4 uses cryptographically secure random bytes. UUID v7 combines the current millisecond timestamp with secure random bits. Web Crypto is required; there is no Math.random fallback. This tool only generates identifiers and does not send requests, store keys, or guarantee absolute uniqueness.
A focused boundary
This page is for idempotent request workflows and ready-to-adapt examples. Use the UUID Generator for general purpose UUIDs.
GOOD TO KNOW
Common questions
Should I make a new key when retrying?
No. Reuse the same key for retries of the same logical operation. Generate a new key when starting a different operation.
Does this call my API?
No. It only generates text locally and shows examples using the placeholder endpoint api.example.com.
Is a prefix part of the UUID?
No. It is added to the transmitted key, so the full Idempotency-Key may not be a bare UUID and must match your API contract.
Is a key guaranteed unique?
No absolute guarantee is made. UUID v4 and v7 use secure randomness, but your service remains responsible for its idempotency policy.