Online Generators for Developers
8 free generators — secure passwords, UUIDs, MD5/SHA hashes, Lorem Ipsum, URL slugs, random numbers, colors, and cron expressions. All run entirely in your browser using the Web Crypto API.
Password Generator
Generate strong, cryptographically random passwords with custom length, symbols, and case rules.
UUID / GUID Generator
Generate RFC 4122 v4 UUIDs (also known as GUIDs) — single or bulk, lowercase or uppercase.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text — paragraphs, sentences, or words for design and demo work.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes of any text or string. Browser-side, no upload.
Slug Generator
Convert any text or title into a clean URL-friendly slug — lowercase, hyphenated, ASCII-only.
Random Number Generator
Generate cryptographically random numbers within a custom min/max range — single or bulk.
Random Color Generator
Generate random colors with hex, RGB, and HSL values — single colors or full palettes.
Cron Expression Generator
Build cron expressions visually — pick minute, hour, day, month, weekday — get the expression.
Browse by Category
Why use OpenFormatter generators?
Web Crypto API
Password, UUID, Hash, and Random Number generators use the browser native crypto API — the same source of randomness used for TLS, JWT signing, and OAuth tokens.
Generated values stay local
No generated value is ever sent to a server. Passwords, hashes, and UUIDs you create are visible only to you. Verifiable in DevTools.
Bulk modes
UUIDs, passwords, random numbers, and slugs all support batch generation — produce hundreds at a time for seeding fixtures and tests.
Instant results
No round-trips, no rate limits, no quota. Generate thousands of values per second from your own machine.
Frequently Asked Questions
Are the generators cryptographically secure?
Yes — Password Generator, UUID Generator, Random Number Generator, and Hash Generator all use the Web Crypto API (crypto.getRandomValues and crypto.subtle), which is the same source of randomness used by browsers for TLS keys. Lorem Ipsum and Cron Generator do not need cryptographic randomness because they produce predictable output.
Are these generators free?
Yes — every generator is free with no usage limits, no signup, no advertising. Generate as many passwords, UUIDs, or hashes as you want.
Do you store the generated values?
No. All generators run entirely in your browser. Generated passwords, UUIDs, and hashes never touch a server. Verify in DevTools — no network requests fire when you click Generate.
Can I use these for production?
Yes for the security generators (Password, UUID, Hash, Random Number) — they use the same Web Crypto API your applications use. The output is suitable for production secrets, identifiers, and tokens.
Why use UUIDs instead of incremental IDs?
UUIDs are globally unique without coordination, work offline, are safe to expose in URLs (they reveal nothing about your data volume), and can be generated client-side without a server round-trip. Use incremental IDs only when you need sequential ordering or compact storage.
What hash should I use for password storage?
Never use MD5, SHA-1, or plain SHA-256 for password storage — they are too fast and vulnerable to GPU-accelerated attacks. Use Argon2id, bcrypt, or scrypt with a per-password salt. The MD5/SHA generators here are for checksums, integrity verification, and educational use, not password hashing.
Can I generate UUIDs in batches?
Yes — the UUID Generator supports generating up to 1000 UUIDs at once. Useful for seeding databases, populating test fixtures, or generating bulk identifiers.
Do you offer a generator API?
No API yet. Each generator runs in JavaScript in your browser using standard Web APIs — you can copy the same logic into your own code (crypto.randomUUID(), crypto.getRandomValues(), crypto.subtle.digest()).
Need other developer tools?
Pair the generators with the rest of OpenFormatter — 200+ tools, all browser-side.