Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Generate a UUID
A v4 UUID carries 122 random bits, while v7 starts with a millisecond timestamp so new rows sort by time: choose v4, v7 or ULID and how many you need, and get…
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Hash a string
Hash any text with the method you pick, so hola mundo hashed with SHA-256 gives a fixed-length fingerprint starting 0b894166.
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Sign and verify a payload
Sign mensaje with the key clave-secreta using HMAC-SHA-256 and you get a signature starting fd7e5bf1 that only someone holding that key can reproduce.
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Decode a JWT
Paste a JWT and read what is inside: a sample token signed with HS256 reveals its subject, its name claim and an expiry of 13 September 2020, so it is flagged…
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Create a signed JWT
Create a signed JWT from your own claims: give a subject, a role such as admin and a shared secret, and you get a ready HS256 token back, or sign with a private…
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Generate a 2FA code
The six-digit code your authenticator shows every 30 seconds comes from a shared secret and the current time: enter the secret to get the current code and the…
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Encrypt text
Encrypt or decrypt text with AES-256-GCM using your own key: the result carries an authentication tag, so a change to even one bit of the encrypted text is…
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Generate a password
Create random passwords that cannot be guessed from earlier ones, one at a time or in batches, such as two passwords of 16 characters.
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Encode and decode Base64
«Año 2026 — ñandú» becomes QcOxbyAyMDI2IOKAlCDDsWFuZMO6 in Base64 and decodes back with every accent intact.
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Convert a Unix timestamp
Turn a Unix timestamp into a readable date and back: 1800000000 is 15 January 2027 at 08:00 UTC, also given in milliseconds, with an optional time zone for the…
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Explain a cron expression
Turn a cron line into a plain sentence: 0 3 * * 1-5 reads as at 3:00 AM, Monday through Friday, so nobody has to count fields from memory or open a reference.
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See the next cron runs
See exactly when a cron expression will fire next, and check that 0 0 1 * * really means midnight on the first of the month rather than a job that runs every…
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Reshape a webhook payload
The email found at data.customer.email lands under correo and the amount 8500 under importe, while a path that does not exist is simply left out: describe the…
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Sign and verify webhooks
A fake payment-succeeded event or a forged order update easily reaches a service that trusts every message: sign your outgoing notifications with a shared…
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Subnet calculator
192.168.1.0/24 gives 254 usable hosts, from 192.168.1.1 to 192.168.1.254: paste a block or an address with its mask to see the network, broadcast, wildcard…
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Regex tester
Check a pattern exactly as your browser will run it: hello in hello world gives one match at position 0, with its numbered and named groups listed.
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Base converter
Rewrite a number from one base into another, anywhere from base 2 to base 36: 1010 in binary is 10 in decimal.
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chmod calculator
chmod 755 is rwxr-xr-x: full rights for the owner, read and execute for the group and everyone else, and 493 as a plain number.
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Damm check digit
Add one digit to any number and catch the typos people actually make: 572 gets the Damm check digit 4 and becomes 5724, and any single wrong digit or swap of…
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Keyword substitution cipher
With the keyword CRYPTO, Hello World becomes Btggj Vjmgp: the keyword opens the cipher alphabet, the remaining letters follow in order, and each letter is…
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Scytale cipher
With 5 columns, HELLOWORLD becomes HWEOLRLLOD: the text is written row by row into a grid, like a strip wound round a rod, and read down each column.
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encodeURIComponent tool
A space becomes %20, & becomes %26 and = becomes %3D, so hello world & café turns into hello%20world%20%26%20caf%C3%A9 and fits inside one query value.
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UTF-16 code unit converter
Type Hi and get 00480069 in big-endian order, that is two code units and 4 bytes. Switch to little-endian and H becomes 48 00 instead.
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Baconian cipher encoder and decoder
Turn letters into Francis Bacon's five-symbol a and b codes, or decode a stream of them back into letters: HI becomes aabbb abaaa.
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Base45 encoder and decoder
AB becomes BB8 in Base45, the RFC 9285 encoding that keeps data within the 45 characters a QR code reads in alphanumeric mode, as EU Digital COVID Certificates…
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Base64url encoder and decoder
“hello world” becomes aGVsbG8gd29ybGQ in Base64url, the URL-safe Base64 of RFC 4648 section 5 that uses minus and underscore instead of plus and slash and drops…
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Columnar transposition cipher
Under the keyword ZEBRAS, WEAREDISCOVEREDFLEEATONCE becomes EVLNACDTESEAROFODEECWIREE: the text is written in rows six columns wide and read column by column in…
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Text to ASCII codes converter
Type Hi and get 72 105, or paste 65 66 67 and read ABC: each character becomes its decimal ASCII code and back, and any code outside 0 to 127 is flagged instead…
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Four-square cipher encoder and decoder
Encrypt letter pairs with Delastelle's four-square cipher and two keywords: HELPME with the keys EXAMPLE and KEYWORD becomes FYNFNE, and the same keywords turn…
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HTML entities encoder and decoder
Tom & Jerry <3 becomes Tom & Jerry <3, so the text can sit inside a tag or attribute without breaking it.
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Morse code translator
HELLO becomes .... . .-.. .-.. --- in International Morse code: every letter, digit and supported punctuation mark turns into its dots and dashes, with a space…
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Quoted-printable encoder and decoder
Turn Hello café into Hello caf=C3=A9 and back again: accents and symbols become equals-sign hex pairs, plain letters stay readable, and soft line breaks keep…
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ROT47 encoder and decoder
Hello becomes w6==@ and the same step brings it back: every printable character from the exclamation mark to the tilde moves 47 places in a ring of 94, while…
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Flag semaphore translator
HELLO becomes five pairs of flag positions, one per letter: E, for instance, is L:HIGH+R:DOWN, left flag high and right flag down.
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Trithemius cipher encoder and decoder
Hello World becomes Hfnos Buytm: the first letter moves 0 places, the second 1, the third 2 and so on, wrapping after Z, while spaces and punctuation stay put.
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Vigenère cipher encoder and decoder
Encrypts “Attack at dawn” with the keyword LEMON into “Lxfopv ef rnhr” and decrypts it back with the same key.
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Affine cipher
Encrypt or decrypt with the affine cipher, which multiplies each letter's position by a and adds b: with a set to 5 and b to 8, AFFINE CIPHER becomes IHHWVC…
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ASCII code lookup
Look up any ASCII character or code and see it every way at once: A is decimal 65, hex 41, octal 101 and binary 1000001.
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Atbash cipher
Mirror every Latin letter across the alphabet, A to Z and B to Y, so Hello, World! becomes Svool, Dliow! and running it again brings the original back.
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Autokey cipher
Encrypt or decrypt with the Autokey cipher, where a short primer is followed by the message itself: with primer KEY, Hello, World! becomes Rijss, Hzfhr! because…
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Base16 RFC 4648 encoder & decoder
Encode text as RFC 4648 Base16, the standard uppercase hex where every byte becomes two characters: Hello turns into 48656C6C6F.
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Base32 encoder & decoder
Encode text as RFC 4648 Base32, the A–Z and 2–7 alphabet behind authenticator secrets: Hello becomes JBSWY3DP.
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Base58 encoder & decoder
“Hello World” becomes JxF12TrwUP45BMd in Base58, using the Bitcoin alphabet of 58 characters without zero, capital O, capital I or lowercase l, so codes stay…
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Flickr Base58 encoder & decoder
“Hello World” becomes iXf12sRWto45bmC in Flickr Base58, the alphabet behind flic.kr short links: no 0, O, I or l, and lowercase before uppercase, the reverse of…
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Text to Base64
“Hello, world!” becomes SGVsbG8sIHdvcmxkIQ== in standard Base64, with the classic plus, slash and equals-sign padding, and any valid Base64 string turns back…
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Ascii85 / Base85 encoder
“Hello, world!” becomes 87cURD_*#TDfTZ)+T in Adobe Ascii85, also called Base85, which packs every four bytes into five printable characters, denser than Base64…
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Beaufort cipher
With the keyword KEY, “Hello, World!” becomes “Danzq, Cwnnh!”, and the same keyword turns it back, because the Beaufort cipher subtracts each letter from the…
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Bifid cipher
With the keyword SECRET, HELLO becomes HKNFO in the Bifid cipher: Félix Delastelle's keyed 5×5 Polybius square splits each letter into row and column digits and…
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Text to binary converter
“Hi” becomes 01001000 01101001: each byte of your text written as eight zeros and ones, one group per byte, while accents and emoji take two to four groups in…
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Braille translator
Type “Hello” and get ⠠⠓⠑⠇⠇⠕: a capital sign followed by five letter cells, ready to paste into a document without any special font.
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Caesar cipher
With a shift of 3, “Hello, World!” becomes “Khoor, Zruog!”: every Latin letter moves three places and the alphabet wraps from Z back to A, while spaces and…
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Gronsfeld cipher
With the key 31415, ATTACKATDAWN encrypts to DUXBHNBXEFZO: each digit shifts the next letter forward by that many places, and the key repeats until the message…
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Text to hex converter
Hello becomes 48656c6c6f: each of its 5 bytes turns into two hex digits, and accented letters or emoji expand to their full UTF-8 bytes.
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Keyboard shift cipher
With an offset of one, hello becomes jraap: each letter slides one key to the right on its own QWERTY row, and the l wraps around to the a.
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Leetspeak translator
Hello World becomes H3110 W0r1d with the classic leetspeak table: e turns into 3, l into 1 and o into 0, while spaces and punctuation stay in place.
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Multiplicative cipher
With key 5, HELLO becomes JUDDS: each letter is multiplied by your key modulo 26, and decrypting uses its inverse, 21.
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NATO phonetic alphabet
SOS spelled for radio is Sierra Oscar Sierra: type letters and digits to get the NATO code words, or paste code words to get the text back.
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Nihilist cipher
HELLO, encrypted with the keyword ZEBRAS and the key 1234, becomes 43 46 46 68 54. The keyword builds a five-by-five letter square, the key adds a repeating…
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Text to octal converter
Hello becomes 110 145 154 154 157: each UTF-8 byte is written as a three-digit octal group. Pick spaces, colons, commas, pipes or no separator at all, and turn…
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Playfair cipher
With the keyword MONARCHY, INSTRUMENTS encrypts to GATLMZCLRQXA: the letters are split into pairs, an X fills the odd end, and each pair is swapped inside a…
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