Discover what shipped recently or was refreshed in the catalog. Use the sort menu to switch between newest releases and recently updated pages.
Count k-length sequences from n symbols when each position may repeat any symbol (n^k cases)
Count k-length ordered selections from n distinct items without reuse—the nPk partial permutation
Calculate maximum heart rate with the Astrand age-based regression formula.
Compute max heart rate via the Ball State University age regression formula.
Calculate body mass index online
Serialize a flat JSON object into an URL-encoded query string for HTTP client construction.
Compute exact years, months, and days between a birth date and a reference date using calendar arithmetic.
Find Gregorian Easter Sunday and related movable feast dates for any year.
Derive an Italian fiscal code from personal data, birthplace, and gender.
Calculate Julian calendar Easter Sunday and linked movable feast dates by year.
Parse JSON and re-serialize with recursively sorted keys for deterministic hashes and diffs.
Derive maximum heart rate with the Cerretelli age-based formula.
Find your Chinese zodiac animal and five-element cycle from a Gregorian birth date
Split long documents into overlapping chunks sized for RAG ingestion or map-reduce agent workflows.
Flip a fair virtual coin for heads or tails—useful for quick decisions and tie-breakers.
Replace runs of spaces, tabs, and newlines with a single space for cleaner plain text.
Blend two colors effortlessly! Use our web app to mix hues and instantly see the resulting color. Try it now
Count multisets of size k from n types when the same element may appear more than once
Count unordered k-subsets from n distinct items without replacement—the binomial n choose k
Project savings growth with compound interest and compounding frequency
Measure contrast ratio between foreground and background hex colors for accessibility compliance.
Turn calendar dates and times into Unix epoch timestamp values.
Estimate max heart rate using the Cooper formula: 220 minus your age in years.
Count every character in a string including spaces and punctuation—complements the word counter.
Count whitespace-separated words in a pasted string—useful for copy limits and readability checks.
Select a time and start a countdown by clicking the start button, easily and online
List of most of the country flags in the world
Parse delimiter-separated values into a JSON array of objects when a header row is present.
Estimate daily calories from lean body mass using the Cunningham RMR formula for athletes
Convert between bytes, KB, MB, GB, and TB using binary (1024-based) factors in your browser.
Find elapsed days, weeks, months, and years between two calendar dates with optional direction.
Find the whole-day difference between a start date and end date using UTC midnight boundaries.
Paste a JWT and view its header and payload decoded directly in the browser.
Recover plaintext from AES ciphertext when you supply the matching passphrase and mode
Decode legacy DES ciphertext for compatibility testing—56-bit DES is not secure today
Decrypt Rabbit stream-cipher output when you know the original secret key bytes
Decode RC4 ciphertext for legacy compatibility checks and capture-the-flag puzzles
Decrypt RC4-drop ciphertext that skips the first 256 keystream bytes before encoding
Decrypt Triple-DES (3DES) ciphertext when the same passphrase and settings were used to encrypt
Merge a base JSON document with an overlay—nested objects combine and arrays concatenate.
Estimate ideal body weight in kg using the Devine clinical formula from height and sex.
Sample uploaded pixels to find the most frequent colors and output CSS-ready hex and RGB swatches.
Calculate bingo prizes using the double approach. Easily calculate your prizes!
Capitalize, uppercase, or lowercase your text easily. Start by pasting your text and clicking the button to begin
Protect messages with AES symmetric encryption—the modern standard for confidential data
Encrypt with single DES for education and legacy interoperability, not production secrets
Encrypt with the Rabbit stream cipher—a fast eSTREAM portfolio algorithm for short payloads
Encrypt with RC4 stream cipher—deprecated in TLS but still found in older applications
Encrypt using RC4-drop, discarding initial keystream bytes to reduce bias attacks
Apply Triple-DES encryption by running DES three times for stronger legacy block protection
Rough token budget from UTF-8 byte length using a chars-per-token heuristic before calling language models.
Apply a regex with flags to an input text and list every match found.
Pretty-print or minify JSON directly in your browser without uploading it.
Convert Arabic numerals (1–3999) into standard Roman numeral notation.
Paste numeric codes (any common separator) and convert them back to text.
Decode Base64-encoded strings back to readable plain text in your browser.
Decode URL-safe Base64url strings back to UTF-8 text for JWT and token debugging.
Convert binary digit sequences (0 and 1) into readable text characters.
Convert human age to equivalent dog years based on size and weight class.
Enter a value in feet and instantly convert it to meters in your browser.
Pick a hex color and read hue, saturation, and lightness channels for theme and design work.
Decode spaced or continuous hex byte sequences back into readable text characters.
Set hue, saturation, and lightness, then convert your HSL color into a HEX value instantly.
Convert HTML entity references back to their original characters.
Re-encode JPEG photos as lossless PNG in the browser—useful when you need PNG containers without re-uploading to a server.
Upload a JPG image, choose quality, and convert it to WEBP without server processing.
Paste JSON data and convert it to XML quickly without sending data to a server.
Convert PNG images to JPEG with adjustable quality for smaller files and legacy compatibility.
Lossy-compress PNG screenshots or graphics to WebP with adjustable quality—all in the browser.
Parse Roman numerals and convert them back to Arabic integers.
Paste text and convert it to a space-separated list of ASCII numeric codes.
Encode plain text or strings into Base64 format instantly in your browser.
Encode plain text to URL-safe Base64 without padding—used in JWT segments and web tokens.
Encode text characters into their 8-bit binary representation string.
Encode each UTF-8 byte of your text as spaced lowercase hex pairs—ideal for debugging and wire dumps.
Convert special characters into HTML-safe entity references for web markup.
Paste text and encode it for safe use in URL query parameters and paths.
Convert Unix epoch seconds into human-readable local date and time.
Paste URL-encoded text and decode it back to its original characters.
Decode WebP photos to JPEG for legacy CMS, email clients, or print workflows that reject WebP.
Paste XML data and convert it to JSON structure directly in your browser.
Generate cryptographically random secrets encoded as Base64 strings.
Export random mock people records as comma-separated CSV spreadsheet data.
Click on the button to start calculating a European VAT number
Generate random Italian fiscal codes (codice fiscale) for testing and demos.
Export randomly generated fake people as a formatted JSON array.
Build numeric identifiers with a valid Luhn check digit for test cards and identifiers.
Compute an MD5 cryptographic hash digest from any text message in your browser.
Pick a random fun pet name from a large curated list of animal names.
Choose a country code and start generating the international IBAN code by clicking on 'Generate'
Select whether the password should be easy to pronounce or complex, then click Generate to start the process
Compute a RIPEMD-160 hash digest from text for checksums and crypto use.
Create RSA self-signed X.509 TLS certificates with PEM keys in the browser.
Produce a SHA-1 hash digest from text using the SHA-1 algorithm in the browser.
Generate SHA-2 family hashes (SHA-256, SHA-384, SHA-512) from text input.
Hash messages with SHA-3 (Keccak) at selectable output bit lengths.
Generate placeholder Lorem Ipsum text by word count, length, or paragraphs.
Create random fake person records with names, addresses, and contact fields.
Generate random names for servers and hosts
Create UUIDs in versions 1, 3, 4, or 5 with optional namespace and name.
Export randomly generated fake person data as structured XML documents.
Export randomly generated person records in YAML format for config and tests.
Inspect pixel width, height, aspect ratio, MIME type, and file size from a local JPEG, PNG, or WebP upload.
Calculate your health metrics, like LDL
Generate an HMAC-MD5 hex digest from a message and secret key for older checksum schemes.
Generate an HMAC-SHA1 hex digest from a message and secret key for legacy integrations.
Generate an HMAC-SHA256 hex digest from a message and secret key—common for API signatures and webhooks.
Flatten JSON arrays or objects into comma-separated rows for spreadsheets and ETL scripts.
Turn JSON documents into readable YAML for configs, Helm charts, and CI pipelines.
Apply Gregorian leap-year rules to any year from 1 to 9999 and see yes or no instantly.
Transform letters into leetspeak substitutions (a→@, e→3, i→1) for stylized nicknames or puzzles.
Generate european license plates
Predict peak heart rate using the Liesen formula from age and gender inputs.
Generate lottery numbers Processing runs locally in your browser.
Preview GitHub-flavored Markdown live in the browser as you type
Look up the Mayan calendar day sign (nawal) associated with your date of birth
Calculate max heart rate using the Mellerowicz age regression formula.
Estimate daily calories with the Mifflin-St Jeor resting metabolic rate equation and activity factor
Estimate ideal body weight in kg using the Miller formula for adjusted clinical targets.
Remove whitespace from JSON documents to shrink payloads for logs or network transfer.
Calculate modulo Processing runs locally in your browser.
Use our tool to calculate your estimated mortgage payments
Enter distance and total time to calculate your average pace per kilometer.
Convert application/x-www-form-urlencoded query strings into a JSON object for agent API tooling.
Estimate password strength with entropy-based scoring in your browser
Calculate bingo prizes in percentage. Easily calculate your prizes!
Compute the percentage increase or decrease between two values quickly.
Count permutations of multiset objects when symbols repeat within fixed-length patterns
Count ordered arrangements of n distinct items taken all at once—the factorial n! formula
Use time and breaks efficiently with the pomodoro timer
Predict your finish time over a target distance from a known pace value.
Expand minified JSON into indented multi-line text for debugging APIs and config files.
Choose the pace, pitch, and voice itself. Paste your text and start reading with your preferred voice
Normalize Unicode text by stripping accents and diacritics for ASCII-friendly filenames or search keys.
Join multiline pasted text into a single line by stripping carriage returns and line feeds.
Scale JPEG, PNG, or WebP to a target width and/or height while preserving aspect ratio in the browser.
Flip character order in a pasted string—handy for puzzles, palindrome checks, and mirrored text experiments.
Estimate ideal body weight in kg using the Robinson formula—a common refinement of Devine.
Roll a fair virtual six-sided die (1–6) for tabletop games and quick random picks.
Roll a fair virtual die with 2 to 1000 sides—d20, d100, or any custom polyhedral count.
Discover your national holidays with this online simulator. Fill in with your country and click on the start button
Randomize the order of non-empty lines in a pasted list using an in-browser Fisher–Yates shuffle.
Build a signed JWT from a JSON payload and shared secret using HMAC-SHA256 in the browser.
Generate sitemap XML content from CSV rows in a quick browser-based workflow
Turn titles into lowercase URL slugs with hyphens—ideal for blog permalinks and file names.
Turn titles into lowercase URL slugs with hyphens for permalinks and file names.
Sort pasted lines in locale-aware alphabetical order—useful for normalizing agent output lists.
Swear in a fanciful way by choosing your favorite swear word yourself!
Estimate maximum heart rate with the Tanaka 208 minus 0.7 times age formula.
Convert temperatures between Celsius, Fahrenheit, and Kelvin with instant results.
Enter a regex pattern with flags and input text to check whether it matches.
Convert the time using different time zones
Get details and time between two dates online
Enter distance and average speed to calculate the estimated travel time for your trip.
Cut text to a maximum character length and append an ellipsis when shortened for previews.
Deduplicate lines while preserving first-seen order—handy for cleaning ID or URL lists from tools.
Create unique resource addresses
Switch between length, weight, and volume units and convert values with one tool.
Measure exact UTF-8 byte size of a string for API payload limits and storage checks.
Optimize your vacation days with this online simulator. Fill in with your days off and start generating now
Validate CSV spreadsheets with configurable delimiter and header row options.
Verify European VAT identification numbers against country format rules.
Paste an IBAN and validate it online
Choose the expected country and verify whether the IBAN is structurally valid for that country.
Check whether an Italian codice fiscale matches formal checksum and format rules.
Validate credit card and identifier numbers using the Luhn mod-10 algorithm.
Check whether a numeric string passes the ISO 7064 MOD-97 control test.
Test whether a pasted string matches common HTTP/HTTPS URL patterns including hostnames and IPv4.
Verify UUID string format and validity for versions 1 through 5.
Validate a JWT signed with HS256 by recomputing the HMAC signature with your shared secret.
Useful running and walking tools
Estimate daily water intake from body weight using ml-per-kg guidelines
Find what percentage the first number represents of the second one.
Paste names and pick one at random with a simple spin-ready selector
Calculator for weekly or monthly work overtime hours
Calculate the value when you take a given percentage of a number.
Paste YAML or YML and get formatted JSON output without uploading files to a server.
Map a birth date to one of twelve Western tropical zodiac sun signs (Aries through Pisces)