UUID v4 ジェネレーター オンライン — 無料で一括生成
暗号学的にランダムな UUID v4 をブラウザで生成。主キー、冪等性トークン、ユニークなリソース ID に便利です。
生成 をクリックすると crypto.randomUUID() で新しい v4 UUID を発行します。必要な数だけ — ログには残りません。
- 何か入力するか貼り付けて開始
よくある利用例
- 1Pre-generate IDs for database records before you have an INSERT round-trip.
- 2Create idempotency keys for retry-safe API calls.
- 3Stamp upload filenames so two simultaneous uploads cannot collide.
よくある質問
Is this UUID v4 or v7?+
v4 — fully random with 122 bits of entropy. It does NOT sort by time. If you need time-ordered IDs use UUID v7 or ULID instead.
How unlikely is a collision?+
Generating 1 billion UUIDs per second for 100 years still leaves less than a one-in-a-billion collision chance. Practically zero for any sensible workload.
Are these UUIDs cryptographically random?+
Yes. crypto.randomUUID() uses the OS CSPRNG (/dev/urandom on Linux, BCryptGenRandom on Windows, SecRandomCopyBytes on macOS).