Generate cryptographically secure UUIDs/GUIDs instantly - random v4 ya time-sortable v7, bulk generation (500 tak), copy & download. Free & 100% browser-based.
UUID (Universally Unique Identifier) ek 128-bit identifier hai jo 36 characters mein display hota hai (32 hex digits + 4 hyphens): 550e8400-e29b-41d4-a716-446655440000. Microsoft ecosystem mein ise GUID kehte hain - dono same cheez hain.
UUIDs ka magic yeh hai ki inhe kahin bhi, bina kisi coordination ke generate kiya ja sakta hai aur duplicate hone ka chance practically zero hai. Isliye yeh distributed systems ke standard identifiers hain.
| Feature | UUID v4 | UUID v7 |
|---|---|---|
| Structure | 122 random bits | 48-bit timestamp + random bits |
| Sortable by time | ❌ No | ✅ Yes |
| DB index performance | Poor (random inserts) | Excellent (sequential) |
| Reveals creation time | No | Yes (timestamp embedded) |
| Best for | General IDs, tokens | Database primary keys |
| Example | f47ac10b-58cc-4372-a567-0e02b2c3d479 | 018f6d2e-7b1a-7cc0-a45e-92b1c3d4e5f6 |
Simple rule: Database primary key chahiye → v7 (index performance 2-5x better). General unique ID chahiye → v4.
Theoretically haan, practically nahi. UUID v4 mein 122 random bits hote hain, matlab 5.3 undecillion (5.3 × 10³⁶) possible values. Perspective ke liye:
128-bit unique identifier (36 characters) jo database keys, API IDs, session tokens ke liye use hota hai. Kahin bhi generate karo, duplicate hone ka chance practically zero.
v4 fully random hai. v7 timestamp se start hota hai - time-sortable hai, isliye database primary keys ke liye better (sequential inserts = faster indexes).
Practically impossible. 1 billion UUIDs per second generate karne par bhi 50% collision chance tak pahunchne mein ~85 saal lagenge.
Kuch nahi - same cheez hai. GUID Microsoft ka term hai (Windows/.NET), UUID universal term hai. Format identical hai.
Haan. Web Crypto API (crypto.randomUUID) use hota hai - cryptographically secure randomness. Sab kuch browser mein locally generate hota hai.