Random String / Token Generator
How it works
Every character is drawn from crypto.getRandomValues — never
Math.random, which is not cryptographically secure. For the
alphanumeric and numeric sets, bytes that would introduce modulo bias are
discarded and redrawn (rejection sampling), so every character is exactly
as likely as any other regardless of the character set's size.
Other tools
Generators
- UUID / GUID GeneratorRandom version-4 UUIDs, or the fixed nil UUID.
- ULID GeneratorSortable, timestamp-prefixed unique IDs.
- Meta Tag & Open Graph GeneratorTitle, description, Open Graph and Twitter Card tags.
- Fake Data GeneratorMock rows of names, emails, phone numbers and IDs.
- Placeholder Image GeneratorAn SVG placeholder image at any size, as a data URI.
- Cron Expression BuilderBuild a cron expression from a simple schedule.
- Markdown Table GeneratorTurn pasted CSV or tab-delimited data into a Markdown table.
- .gitignore GeneratorAssemble a .gitignore from common language and editor templates.
- License Text GeneratorFull open-source license text — MIT, Apache-2.0, GPL-3.0 and more.
Text
- Word CounterLive word, character and reading-time stats.
- Case ConverterUPPER, lower, Title, camelCase, snake_case and more.
- Lorem Ipsum GeneratorPlaceholder text by words, sentences or paragraphs.
- Diff CheckerLine-by-line diff of two text blocks via LCS.
- Text CleanerTrim, collapse blanks, dedupe and sort lines of text.
- Regex TesterTest JavaScript regular expressions against your own text — matches, indices and capture groups.
- Markdown PreviewerLive preview of a small Markdown subset — headings, bold, italic, code, links and lists.
- Slug GeneratorTurn any text into a lowercase, URL-safe slug — accents stripped, punctuation collapsed.
- Unicode Code Point InspectorPer-character code point, U+ hex value and UTF-8 byte length, including emoji outside the BMP.
- Word Frequency AnalyzerCase-insensitive word counts, ranked most to least common.
- Regex Cheat SheetBrowsable reference of common regex patterns and syntax.
- Readability Score CalculatorFlesch-Kincaid reading ease and grade level of your text.
- Text Truncator / Excerpt GeneratorTruncate text to a length at a word boundary, with an ellipsis.
- Find and Replace (Regex)Replace every regex match in text with a replacement pattern.
Code & data
- JSON FormatterPretty-print, minify and validate JSON.
- Base64 Encoder / DecoderEncode or decode Base64 with Unicode support.
- XML FormatterPretty-print and validate XML, with clear errors on mismatched tags.
- JSON Path EvaluatorPull a value out of JSON with a simple dot/bracket path.
- CSS Beautifier / MinifierBeautify or minify CSS — string- and comment-aware.
- SQL FormatterBeautify SQL by keyword — SELECT, FROM, WHERE, JOIN and more.
- HTML FormatterIndent nested HTML tags, with void elements handled correctly.
- YAML ⇄ JSON ConverterConvert YAML to JSON or JSON back to YAML.
- SVG Formatter / MinifierPretty-print or minify SVG markup.
- JSON to TypeScript ConverterGenerate a TypeScript interface from a JSON sample.
- JSON Diff CheckerStructural differences between two JSON documents.
- INI / Properties File ParserConvert INI or .properties key=value files to JSON and back.
- GraphQL Query FormatterPretty-print a GraphQL query or mutation.
- .env File ParserConvert a .env file to JSON and back, comments and quotes intact.
- CSV Diff CheckerRow-by-row and cell-by-cell differences between two CSV files.
Encoding
- URL Encoder / DecoderPercent-encode or decode URLs and query strings.
- HTML Entity Encoder / DecoderEscape or unescape HTML entities like & and <.
- Base32 Encoder / DecoderEncode or decode RFC 4648 Base32 text.
- Hex ⇄ Text ConverterConvert text to hexadecimal bytes and back.
- Binary ⇄ Text ConverterConvert text to binary bytes and back.
- CSV ⇄ JSON ConverterConvert CSV to JSON or JSON back to CSV, with proper quoted-field handling.
- Query String Parser & BuilderSplit a query string into key/value pairs, or build one from pairs.
- String Escape / UnescapeEscape or unescape strings for JSON/JS literals or regex patterns.
- Punycode / IDN ConverterConvert a domain name between Unicode and Punycode.
- File to Base64 ConverterConvert any local file to a Base64 data URI.
- ROT13 / Caesar CipherShift letters by any amount — ROT13 and beyond.
- Morse Code TranslatorConvert text to Morse code and back.
- Base58 Encoder / DecoderEncode or decode Base58, the Bitcoin-address alphabet.
Hashing & Security
- Hash GeneratorGenerate SHA-1, SHA-256, SHA-384 and SHA-512 hashes.
- HMAC GeneratorGenerate keyed HMAC signatures with SHA-256/384/512.
- JWT DecoderDecode a JWT header and payload — no signature verification.
- Password Strength CheckerEstimate password entropy and flag common weaknesses.
- Credit Card Number ValidatorCheck a card number against the Luhn checksum.
- IBAN ValidatorCheck an IBAN's shape and mod-97 checksum.
- JWT EncoderBuild and sign a JWT with a header and payload.
- Basic Auth Header Encoder / DecoderBuild or decode an HTTP Basic Authorization header.
- CRC32 Checksum CalculatorCompute the CRC32 checksum of text or a file.
- Password Policy CheckerCheck a password against configurable length and character rules.
Web & Network
- URL ParserBreak a URL into protocol, host, port, path, query and hash.
- User-Agent ParserBest-effort browser, OS and device type from a UA string.
- HTTP Status Code ReferenceBrowsable table of HTTP status codes with lookup.
- CIDR / Subnet CalculatorNetwork, broadcast, mask and usable host range from CIDR.
- IP Address ConverterConvert IPv4 between decimal, integer, binary and hex.
- MAC Address FormatterReformat a MAC address between colon, dash, dot and none.
- HTTP Header ParserParse raw HTTP headers into a readable table.
- Sitemap ValidatorCheck an XML sitemap against the sitemap protocol.
- DNS Record Type ReferenceBrowsable reference of DNS record types and what each is for.
- User-Agent String BuilderBuild a realistic User-Agent string from browser, OS and device.
- MIME Type LookupLook up the MIME type for a file extension, or the reverse.
Numbers & CS
- Bitwise Operations CalculatorAND, OR, XOR, NOT, and bit shifts with binary display.
- Two's Complement CalculatorConvert signed integers to two's complement binary and back.
- IEEE 754 Float ConverterConvert decimals to IEEE 754 single/double-precision bits and back.
- ASCII Table ReferenceFull 7-bit ASCII table with character, hex, and control-code lookup.
- Levenshtein Distance CalculatorEdit distance and similarity percentage between two strings.
- Number FormatterAdd thousands separators or convert number formats.
- Prime Number CheckerCheck primality and list prime factors.
- GCD / LCM CalculatorGreatest common divisor and least common multiple.
- Big-O Complexity ReferenceBrowsable reference of common time-complexity classes.
- Matrix CalculatorAdd, multiply or find the determinant of small matrices.
- Combinatorics CalculatorPermutations (nPr) and combinations (nCr) of n items.
Color & Design
- Color ConverterConvert colors between HEX, RGB, HSL and CMYK.
- Color Contrast CheckerCheck WCAG AA/AAA contrast ratio between two colors.
- Color Shade GeneratorGenerate a shade and tint ramp from any color.
- CSS Gradient GeneratorBuild linear and radial CSS gradients from color stops.
- Color Palette GeneratorComplementary, triadic and analogous color schemes.
- CSS Box-Shadow GeneratorBuild a CSS box-shadow with a live preview.
- CSS Clamp() Fluid Typography CalculatorA responsive clamp() font-size from a min and max size.
- Color Blindness SimulatorSee how a color looks under common color vision deficiencies.
Date & Time
- Timestamp / Epoch ConverterConvert Unix epoch seconds or milliseconds to a date, or a date to an epoch value.
- Date Format ConverterReformat a date using YYYY, MM, DD, HH, mm, ss tokens — always in UTC.
- ISO 8601 Duration ParserParse a PnYnMnDTnHnMnS duration into years, months, days, hours, minutes and seconds.
- Cron Expression Parser & ExplainerParse a 5-field cron expression into plain English and see its next run times.
- Date Add / Subtract CalculatorAdd or subtract days, months or years from a date.
- Business Days CalculatorWeekdays between two dates, weekends excluded.
- Meeting Time Overlap FinderOverlapping working hours across two or more time zones.
- Relative Time FormatterFormat a timestamp as "3 hours ago" or "in 2 days".