Generators & Developer Utilities
A free collection of online developer utilities — generate UUIDs, compute hash digests, convert Unix timestamps, and test regular expressions. Everything runs locally in your browser.
UUID Generator
Generate random UUIDs (v4) or time-ordered UUIDs (v7) in bulk, ready to copy.
Open UUID →Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text instantly.
Open Hash →Unix Timestamp Converter
Convert a Unix timestamp to a human date, or a date to Unix seconds — with relative time.
Open Timestamp →Regex Tester
Test a regular expression against sample text with live match highlighting and capture groups.
Open Regex →What these developer utilities do
This hub gathers the small, everyday helpers that engineers reach for dozens of times a day: creating unique identifiers, producing file checksums, translating epoch numbers into readable dates, and debugging tricky patterns. Each tool is focused, instant, and free. Because Formatly is 100% client-side, your inputs are processed by JavaScript running in your own browser — nothing is uploaded to a server, logged, or stored remotely.
- UUID generator — produce universally unique identifiers (such as random version-4 UUIDs) for database keys, request IDs, and test fixtures.
- Hash generator — compute cryptographic digests and checksums (for example MD5, SHA-1, SHA-256) to verify file integrity or fingerprint data.
- Unix timestamp converter — turn epoch seconds or milliseconds into human-readable dates and back again.
- Regex tester — write a regular expression, paste sample text, and see matches and capture groups highlighted in real time.
Unique identifiers (UUIDs) explained
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value usually written as 32 hexadecimal digits in five hyphen-separated groups, like 550e8400-e29b-41d4-a716-446655440000. The most common form is version 4, which is generated from random data. UUIDs are designed so that you can create them independently on different machines without coordinating, yet the chance of a collision is negligible. That makes them ideal for primary keys, distributed systems, idempotency tokens, and any case where you need an identifier without asking a central authority for one.
Hashes, checksums, and Unix time
A cryptographic hash maps input of any size to a fixed-length digest — for example, SHA-256 always produces 64 hexadecimal characters. The same input always yields the same digest, but the function is one-way: you cannot reverse a digest back into the original data. This is why hashing is not encryption — there is no key and no way to decrypt it. Hashes are used for integrity checks (does this download match the published checksum?), de-duplication, and fingerprinting.
Unix time (epoch time) counts the number of seconds elapsed since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. A value like 1733616000 is compact, timezone-neutral, and easy to compare or sort, which is why APIs, logs, and databases store time this way. Some systems use milliseconds instead, so the converter handles both. Finally, a regex tester lets you experiment with regular expressions safely — adjusting the pattern and flags until it matches exactly what you intend — without running half-built patterns against production data.
Guides
Learn the concepts behind these tools:
Generators & Developer Utilities FAQ
What is the difference between a hash and encryption?
They solve different problems. Encryption is reversible: with the correct key you can decrypt ciphertext back into the original data. A hash is a one-way function — it produces a fixed-length digest from your input, and there is no key and no way to reverse it back into the original. For that reason, hashing is not a way to keep data confidential; it is used to verify integrity (checksums) and to fingerprint data. If you need to hide data and recover it later, you want encryption, not a hash.
Is my data safe when I use these tools?
Yes. Every tool on Formatly runs 100% client-side in your browser using JavaScript — your UUIDs, files, timestamps, and regex inputs are never uploaded, transmitted, or stored on a server. This is especially important for the hash generator and regex tester, where you might work with sensitive strings or proprietary patterns. Because the work happens locally, you can even use the tools offline once the page has loaded.
What is a UUID and when should I use one?
A UUID (Universally Unique Identifier) is a 128-bit value, typically shown as 32 hex digits in five groups like 550e8400-e29b-41d4-a716-446655440000. Use one whenever you need a unique key that can be generated independently — without a central counter — such as database primary keys, request or trace IDs, file names, idempotency keys, or test data. Version-4 UUIDs are random, so two systems can mint them at the same time with a vanishingly small chance of collision.
How do I read or convert a Unix timestamp?
A Unix timestamp is the number of seconds since 00:00:00 UTC on 1 January 1970 (the "epoch"). For example, 1733616000 corresponds to a specific moment in UTC. Paste the number into the converter to get a human-readable date and time, or enter a date to get the timestamp back. Watch the units: many platforms (including JavaScript's Date.now()) use milliseconds, which are 13 digits, while classic Unix time uses 10-digit seconds.
Which hash algorithm should I choose?
It depends on your goal. SHA-256 is a solid default for verifying file integrity and general fingerprinting. MD5 and SHA-1 are still common for quick, non-security checksums and matching against legacy published values, but they are considered cryptographically broken and should not be used for security purposes such as protecting passwords or signatures. For storing passwords specifically, a general-purpose hash is the wrong tool — use a dedicated password-hashing scheme designed to be slow.
What is a regex tester for?
A regex tester lets you build and debug a regular expression interactively. You type a pattern (and flags such as global or case-insensitive), paste in sample text, and instantly see which substrings match and what each capture group contains. It is far faster than editing a pattern in code and re-running your program, and it helps you catch mistakes — like a greedy quantifier matching too much — before the expression reaches production. On Formatly the matching happens in your browser, so your test data stays private.