Free JSON and JavaScript tools that never leave your browser
Format, convert, compare and decode developer data with 21 fast tools. Everything runs on your device, so tokens, API responses and private code are never uploaded.
JSON Tools
JSON Formatter & Validator
Pretty-print, minify and validate JSON with line and column errors, tree view and key sorting.
JSON to CSV Converter
Turn an array of JSON objects into CSV for Excel or Sheets, with nested fields flattened.
CSV to JSON Converter
Parse CSV or TSV into JSON objects with type detection and optional nesting.
JSON to YAML Converter
Convert JSON to clean, readable YAML for Kubernetes, CI and config files.
YAML to JSON Converter
Parse YAML, including anchors and multiple documents, into JSON with line-level errors.
JSON Diff & Compare
Compare two JSON documents and list added, removed and changed values by path.
JSONPath Tester
Run JSONPath queries against your JSON with filters, slices and recursive descent.
JSON Schema Generator & Validator
Generate a JSON Schema from a sample and validate documents against it.
JSON to TypeScript Types
Generate TypeScript interfaces from a JSON sample, with optional fields and unions.
JavaScript Tools
JavaScript Minifier
Minify and compress JavaScript with Terser: mangle names, drop dead code, optionally remove console calls.
JavaScript Beautifier
Reformat minified or messy JavaScript with consistent indentation and brace style.
Regex Tester & Explainer
Test JavaScript regular expressions with live highlights, groups and a plain-English explanation.
JWT Decoder
Decode a JSON Web Token locally: header, payload, expiry. Nothing is sent anywhere.
Encoders & Converters
Base64 Encoder & Decoder
Encode text to Base64 or decode it back, with UTF-8, URL-safe and padding options.
URL Encoder & Decoder
Percent-encode or decode URLs and query strings, with component, whole-URL and form modes.
Hash Generator (SHA-256, MD5)
Compute SHA-256, SHA-512, SHA-1, MD5 and HMAC for text or files, locally.
UUID Generator (v4 & v7)
Generate random v4 and time-ordered v7 UUIDs in bulk, and inspect any UUID.
Unix Timestamp Converter
Convert Unix timestamps to dates and back, with unit detection and time zones.
HTML Entity Encoder & Decoder
Escape HTML special characters or decode named and numeric entities.
Text Diff Checker
Compare two texts side by side with line and word highlights and a unified diff.
EDI Tools
Why use DevPocket
Private by design. Each tool is plain JavaScript running inside the page. There is no server that receives your input, no account and no upload step, which matters when the text you are pasting is a production API response or an access token.
Quick to open. Every page is a small static shell. The code for a tool, including heavier libraries such as the minifier, is downloaded only when you open that tool, and long-running work happens in a background worker so the page never freezes.
Built for real work. JSON errors are reported with exact line and column numbers. Settings such as indentation are remembered, files can be dropped onto the input, results copy with one click, and Ctrl+Enter runs the main action. Small inputs can be shared as a link when you choose to, and secrets never are.
How the tools fit together
Most real tasks are chains. Format a response to read it, find a value with the JSONPath tester, compare it with yesterday's payload in the JSON diff, then generate TypeScript types or a JSON Schema for it. Every tool page links to the natural next step.