A workbench of developer tools that never leave your browser.
Free developer tools that run entirely in your browser: format JSON, generate UUIDs, count words and more. No upload, no sign-up, nothing sent to a server.
Formatters
Generators
Chmod CalculatorTurn file permissions into octal, symbolic form and a command.Cron Every 15 MinutesA quarter-hour schedule, with the offsets.Cron Every 30 MinutesHalf-hourly schedules, and the trap next door.Cron Every 5 MinutesA five-minute schedule, and how to offset it.Cron Every Day at MidnightA daily midnight job that survives the clocks.Cron Every HourHourly, two-hourly and six-hourly schedules.Cron Every MinuteRun a job every minute, without stacking runs.Cron Every MondayWeekly Monday jobs, without the off-by-one.Cron Every MonthMonthly and quarterly jobs, last day included.Cron Expression GeneratorExplain a cron schedule and preview its next runs.Hash GeneratorSHA-1, SHA-256, SHA-384 and SHA-512 digests of any text.Markdown Table GeneratorGrid or pasted CSV into an aligned GFM table.Password GeneratorRandom passwords and passphrases, with honest entropy.Random Number GeneratorPick numbers in a range, drawn without modulo bias.UUID GeneratorGenerate UUID v4 and v7 identifiers in bulk.
Text tools
Lorem Ipsum GeneratorPlaceholder paragraphs, sentences or words, as text or HTML.Remove Duplicate LinesStrip repeated lines from a list and count what went.Sort LinesSort lines alphabetically, naturally, numerically or by length.Text Diff CheckerLine-by-line comparison with word-level highlighting.Word CounterCount words, characters and reading time as you type.Word Frequency CounterRank words and phrases by how often they occur, then export.
Encoders & decoders
Base64 Encoder and DecoderEncode and decode Base64 with correct UTF-8.HTML Entity Encoder and DecoderEscape and unescape HTML entities safely.JSON Escape and UnescapeTurn text into a JSON string value, and back.JWT DecoderRead a JWT header, payload and expiry safely.Morse Code TranslatorText to Morse and back, with the whole ITU table on the page.Text to Binary ConverterTurn text into UTF-8 bits, and bits back into text.URL Encoder and DecoderPercent-encode and decode URLs and query values.
Converters
Byte ConverterBytes across the 1000 and 1024 scales, side by side.Case ConverterNine naming conventions from any input, acronyms included.CIDR CalculatorIPv4 prefixes, host ranges and usable counts.Colour ConverterSix notations, CSS names and WCAG contrast at once.CSV to JSON ConverterCSV into JSON with a parser that survives quotes and line breaks.Date Difference CalculatorDays, weeks, months and working days between two dates.IP Address ConverterEvery way to write one IPv4 or IPv6 address, side by side.JSON to CSV ConverterJSON arrays into CSV that Excel opens without mangling a column.JSON to TypeScript ConverterJSON in, TypeScript interfaces out — unknown, never any.JSON to YAML ConverterJSON into YAML, quoted where YAML would misread it.Number Base ConverterAny base from 2 to 36, with BigInt precision.Slug GeneratorTitles into clean URL slugs, accents folded.Unix Timestamp ConverterEpoch to date and back, in seconds or milliseconds.
Inspectors & testers
HTTP Status CodesAll 63 registered codes, searchable, plus the ones servers invented.JSON DiffCompare two JSON documents by value, with a JSON Patch out.MIME Type LookupExtension to media type and back, with the header to send.Regex TesterMatch, replace and read a regular expression.URL ParserEvery part of a URL, named and explained.
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