Developer tools
Everyday utilities for programmers: encode and decode text, test regular expressions, convert between formats and explain cron schedules, without sending your input to a server.
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Base64 encoder
Encode UTF-8 text as standard Base64 or Base64url. Encoding does not encrypt data.
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Base64 decoder
Decode standard Base64 or Base64url into strict UTF-8 text or hexadecimal bytes. Invalid padding and unused bits are rejected.
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URL encoder
Percent-encode UTF-8 text for one URL component, form data or a whole URL. A whole URL keeps reserved separators.
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URL decoder
Decode percent escapes. Form mode changes + to a space. Invalid escapes or invalid UTF-8 produce an error.
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HTML entity encoder
Escape text for an HTML text node or quoted attribute. This is not an HTML sanitizer or a JavaScript/CSS escaping tool.
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HTML entity decoder
Decode numeric references and common named entities, including amp, lt, gt, quot, apos, nbsp, copyright, currency and punctuation. Unsupported names produce an error. Output remains plain text.
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UUID generator
Generate random version 4 UUIDs with the browser cryptographic random generator. Input text is ignored.
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URL parser
Split an absolute URL into its components and ordered query pairs. Passwords are hidden by default. This tool does not open the URL.
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Query string builder
Turn a JSON object into a form-encoded query string. Arrays create repeated keys; null becomes an empty value. Nested objects are rejected.
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Query string parser
Decode a query string into ordered key/value pairs, retaining repeated keys and empty values. + means a space. Invalid UTF-8 and percent escapes are rejected.
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Unicode inspector
Show Unicode code points, UTF-16 units and UTF-8 bytes. A visible symbol can contain several code points. Unpaired surrogates are rejected.
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UTF-8 byte counter
Count actual UTF-8 bytes, Unicode code points and UTF-16 code units. Optionally normalize equivalent Unicode sequences before counting.
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Hex encoder
Encode UTF-8 text as hexadecimal byte values. Emoji and accented letters can use more than one byte.
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Hex decoder
Decode hexadecimal bytes into strict UTF-8 text or compact hex. ASCII whitespace is allowed; odd digits, prefixes and other separators are rejected.
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Integer base converter
Convert signed whole numbers between bases 2 and 36 without floating-point rounding. Matching 0b, 0o and 0x prefixes are allowed. Fractions are not supported.
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HTTP status reference
Look up common standardized HTTP response codes and their meaning. Application-specific codes may have a different or nonstandard meaning.
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JSON to YAML converter
Convert JSON to block-style YAML 1.2. Ambiguous strings are quoted, multi-line strings become literal blocks, and key order is kept.
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YAML to JSON converter
Convert common YAML (mappings, lists, quoted and block text, flow [ ] and { }) to JSON. Anchors, aliases, tags and multiple documents are rejected.
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XML formatter
Check that XML is well-formed and pretty print or minify it. The first error is reported with its line and column. Entities are never expanded.
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JSON minifier
Validate JSON and remove all whitespace outside strings, then report the size before and after in UTF-8 bytes and the percent saved.
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JSON to TypeScript
Generate TypeScript interfaces or types from a JSON sample. Array items are merged, missing fields become optional and mixed values become unions.
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CSV to Markdown table
Turn CSV with a header row into a GitHub-flavored Markdown table. Quoted fields follow RFC 4180, pipes are escaped and columns are padded.
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HTML to text converter
Strip HTML tags to readable plain text. Scripts and styles are dropped, blocks and list items become lines and bullets, and entities are decoded.
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Markdown to HTML converter
Convert common Markdown (headings, lists, links, images, code, quotes, emphasis) to HTML source. Raw HTML is escaped unless you allow it.
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Regex tester
Test a JavaScript regular expression on text: list each match with its index and capture groups, and preview a replacement. Up to 1,000 matches.
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Cron expression explainer
Explain a standard 5-field cron expression or macro such as @daily in plain English and list its next 5 run times in UTC.
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CRC-32 checksum calculator
Calculate the CRC-32 checksum of UTF-8 text, as used by ZIP, PNG and gzip, or the CRC-32C variant. Shows hex and decimal.
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Base32 encoder
Encode UTF-8 text as RFC 4648 Base32 or Base32hex, with or without = padding. Encoding is not encryption.
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Base32 decoder
Decode RFC 4648 Base32 or Base32hex to UTF-8 text or hex bytes. Case and spaces are ignored; bad characters and padding are reported.
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String escape and unescape
Escape or unescape text for a JavaScript string, JSON string, CSV field, SQL single-quoted string or regex literal.
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Text to binary converter
Convert text to 8-bit binary, one group per UTF-8 byte. Choose the separator and optionally show decimal byte values too.
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Binary to text converter
Convert 8-bit binary groups back to UTF-8 text. Spaces are optional, but every byte needs exactly 8 bits and the bytes must be valid UTF-8.
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SQL IN list builder
Turn a pasted list into a SQL IN (...) clause. Quotes text, doubles single quotes, can remove duplicates and split long lists into chunks.
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JSON Lines to JSON converter
Convert JSON Lines (one JSON value per line) to a JSON array, or a JSON array to JSON Lines. The first invalid line is reported.
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