Free Online Developer Tools
Format JSON, test regular expressions, convert timestamps and generate hashes without leaving the browser. Pocketful developer tools are made for short debugging and data preparation tasks, with useful errors and copy-ready output. Text and files for supported tools are processed locally, so source snippets, secrets and payloads are not uploaded to Pocketful.
Popular tasks
Workflows
Prepare structured data
Check an encoded value
All Developer Tools
JSON Formatter
Beautify, minify & validate JSON. Syntax errors pinpointed to line:column.
JSON to Model
Turn JSON, iOS NSLog or Android log prints into Swift, Kotlin, TS, Dart, Java & Python models.
Base64 Encoder
UTF-8-safe Base64 encode/decode (CJK & emoji proof), URL-safe mode.
UUID Generator
Crypto-secure v4 UUIDs in bulk (up to 500), uppercase/no-hyphen options.
Regex Tester
Live match highlighting + capture groups. JavaScript flavor, all local.
Markdown Previewer
Live GFM preview with tables & code. Export .md or standalone .html.
HTML Preview
Live-render HTML in a sandboxed frame as you type. Open full page, download or share by link.
Timestamp Converter
Unix epoch ↔ date, live current timestamp, seconds/ms auto-detect, local & UTC.
Hash Generator
MD5, SHA-1 & SHA-256/384/512 from text or files — all at once, with checksum verify.
HMAC Generator
HMAC-SHA256/384/512 signatures with a secret key. Hex & Base64 output, Web Crypto local.
URL Encoder & Decoder
Encode/decode URLs and query strings. Component vs full URI modes.
Word Counter
Count characters, words, lines & CJK chars as you type. Zero upload.
Why use Pocketful developer tools
Pocketful keeps small utilities fast and disposable. There is no workspace to configure, and local processing avoids pasting private payloads into a remote formatter or converter.