100% in-browser
Developer Tools
A toolkit of free developer utilities that run entirely in your browser — format and validate JSON, encode and decode Base64, decode JWTs, test regular expressions, generate UUIDs, and convert between data formats, with nothing ever sent to a server.
{}
JSON Formatter & Validator
Pretty-print, minify and validate JSON, with inline error messages.
64Base64 Encoder / Decoder
Encode text to Base64 or decode it back — full UTF-8 support.
%URL Encoder / Decoder
Percent-encode strings for safe use in URLs, or decode them back.
#Hash Generator
Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text.
JWTJWT Decoder
Decode a JSON Web Token's header and payload locally — no verification.
⏲Cron Expression Parser
Validate a cron expression and preview the next scheduled run times.
.*Regex Tester
Test a regular expression against text and highlight every match.
⇄CSV ⇄ JSON Converter
Convert CSV to a JSON array and JSON back to CSV.
&HTML Entity Encoder
Encode text to HTML entities or decode entities back to text.
∑File Checksum (WASM)
Compute CRC-32, Adler-32 and SHA-256 of any file — powered by WebAssembly.
TSJSON to TypeScript
Generate TypeScript interfaces from a JSON sample, inferring types recursively.
</>XML Formatter
Pretty-print XML with indentation or minify it down to a single line.
⌗SQL Formatter
Format SQL by uppercasing keywords and putting clauses on their own lines.
⊟HTML Minifier
Minify HTML by removing comments and collapsing extra whitespace.
⊠CSS Minifier
Minify CSS by stripping comments and unnecessary whitespace.
"JSON String Escaper
Escape or unescape a string for safe use inside a JSON document.
\nBackslash Escaper
Escape or unescape backslash sequences such as \n, \t and \uXXXX.
?=Query String Parser
Parse a URL query string into JSON and convert JSON back into a query string.
⌖URL Parser
Break a URL into its protocol, host, port, path, query and hash parts.
UAUser-Agent Parser
Identify the browser, rendering engine and operating system from a user-agent string.
⌨Keyboard Event Tester
See the key, code and keyCode for any key you press, with modifier flags.
⚑HTTP Status Codes
Look up the name and meaning of any HTTP status code by number or text.
755Chmod Calculator
Convert between symbolic and octal Unix file permissions, in both directions.
⊞}JSON Flatten / Unflatten
Flatten nested JSON to dot-notation keys, or rebuild nested objects from flat keys.
A↓}JSON Key Sorter
Recursively sort the keys of a JSON object, ascending or descending.
}<JSON to XML
Convert a JSON object into an indented XML document.
<↓HTML to Markdown
Convert basic HTML into clean Markdown as you type.
{ }CSS Beautifier
Format and indent minified CSS with proper newlines and spacing.
.gi.gitignore Generator
Build a combined .gitignore file from common language and tool templates.
}±JSON Diff
Compare two JSON objects and list every added, removed and changed value by path.
▦<HTML Table Generator
Turn comma, tab or semicolon separated rows into clean HTML table markup with a preview.
▦|Markdown Table Generator
Convert CSV or TSV data into a padded, aligned GitHub-flavored Markdown table.
ULIDULID Generator
Generate sortable, lexicographically ordered, unique ULID identifiers.
nanoNano ID Generator
Generate compact, URL-safe, unique IDs with a custom size and alphabet.
❄Snowflake ID Decoder
Decode a Twitter or Discord snowflake ID into its timestamp, worker, process and sequence.
45Base45 Encoder/Decoder
Encode and decode Base45 as defined by RFC 9285, used in EU COVID QR codes.
xnPunycode / IDN Converter
Convert international domain names to Punycode (xn--) ASCII and back to Unicode.
NFCUnicode Normalizer
Normalize Unicode text using the NFC, NFD, NFKC or NFKD forms.
mimeMIME Type Lookup
Find the MIME content type for a file extension, or search by MIME type.
.extFile Extension Info
Look up what a file extension means, its category and typical MIME type.