Developer tools
Developer tools
Formatting, validating, encoding and debugging, all in the tab you already have open. Every tool runs locally, so an API response you paste in — auth headers, customer records and all — never leaves the browser.
Every developer tool
JSON Formatter
Pretty print, validate and beautify JSON instantly.
Open toolMIME Type Lookup
Find the MIME type for a file extension, or the extensions behind a type.
Open toolUser Agent Parser
Identify the browser, OS, device, engine and bot markers behind a User-Agent.
Open toolRegex Tester
Test patterns against sample text with live match highlighting.
Open toolBase64 Decoder
Decode Base64 into text, JSON, XML, HTML or an image, with format detection.
Open toolBase64 Encoder
Encode and decode Base64 for text, files and data URIs.
Open toolUUID Validator
Validate UUIDs in bulk and detect their version, variant and formatting issues.
Open toolUUID Generator
Generate v1, v4, v6 and v7 identifiers in bulk, and validate existing ones.
Open toolDiff Checker
Compare two blocks of text or code, see what changed, and merge the two.
Open toolCron Expression Generator
Build, validate and explain cron expressions, with a preview of the next runs.
Open toolURL Encoder
Percent-encode URLs, query strings and text for safe transmission.
Open toolURL Decoder
Decode percent-encoded URLs, query strings and text back into readable form.
Open toolUnix Timestamp Converter
Convert Unix timestamps to dates and back, in seconds, milliseconds, microseconds or nanoseconds.
Open toolSQL Formatter
Format queries with consistent keyword casing and indentation.
Open toolSQL Minifier
Collapse queries to a single line and strip comments safely.
Open toolHTML Formatter
Pretty print and indent HTML with consistent attribute wrapping.
Open toolCSS Formatter
Format stylesheets with consistent rules, nesting and spacing.
Open toolJavaScript Formatter
Beautify JavaScript and TypeScript with predictable indentation.
Open toolYAML Formatter & Validator
Format and validate YAML, with comments preserved and multi-document support.
Open toolHTTP Status Codes
Look up any status code with its meaning and typical use.
Open toolJSON Viewer
Explore large JSON as a collapsible tree with search and copyable paths.
Open toolJSON Minifier
Strip whitespace from JSON and see exactly how many bytes it saved.
Open toolJSON Validator
Check JSON against the spec and get the exact line, column and cause.
Open toolJSON Compare
Diff two JSON documents structurally and see what was added or changed.
Open toolJSON Diff
See what changed between two JSON documents in a Git-style unified diff.
Open toolJSONPath Tester
Write and test JSONPath expressions against JSON with instant results.
Open toolXML Formatter
Beautify, validate and explore XML with an interactive tree view.
Open tool
The JSON toolkit
Seven tools cover a payload end to end: pretty-print it, get the exact line and column of a parse error, open a collapsible tree over something too large to scroll, work out a JSONPath expression before it goes into code, compare two documents structurally or as a Git-style unified diff, and check the byte cost of minifying.
Formatters and minifiers
SQL, HTML, CSS, JavaScript, YAML and XML each have a formatter here, and SQL has a minifier that strips comments without touching string literals.
Worth being plain about what a formatter does: it changes whitespace, indentation and casing. It does not change what the code means.
Encoding, identifiers and time
- Base64 and URL encoding and decoding, in both directions.
- UUID v1, v4, v6 and v7 generated in bulk, plus a validator that reports the version and variant.
- Cron expressions built from fields, with the next run times previewed.
- Unix timestamps converted both ways — for log lines and for reading a JWT expiry claim.
Reference lookups
The three questions that interrupt debugging most often: what does this HTTP status code mean, what Content-Type does this file extension need, and what browser, OS and device is this User-Agent string?