Developer tools

• Format JSON

  Beautify or minify JSON. DeveloperOpen

• Validate JSON

  Check if JSON is valid and find the exact error position. DeveloperOpen

• Encode a URL

  Percent-encode text for safe use in URLs. DeveloperOpen

• Decode a URL

  Decode percent-encoded URLs back into readable text. DeveloperOpen

• Format XML

  Pretty-print, minify and check XML, with the exact line of any error. DeveloperOpen

• Format HTML

  Tidy up HTML with consistent indentation and line breaks. DeveloperOpen

• Format or minify CSS

  Beautify CSS for reading, or minify it for a smaller file. DeveloperOpen

• Format JavaScript

  Beautify minified or messy JavaScript with consistent indentation. DeveloperOpen

• Test a regular expression

  Try regular expressions live: every match, its groups and the result of a replace. DeveloperOpen

• Make or check a bcrypt hash

  Hash a password with bcrypt at the cost you choose, or check a password against a bcrypt hash. DeveloperOpen

• Decode a JWT

  Read a JSON Web Token: header, claims, expiry, and check its signature. DeveloperOpen

• Encode Base64

  Encode text or any file to Base64, URL-safe Base64 or a data: URL. DeveloperOpen

• Decode Base64

  Turn Base64 back into text, or into the file it contains. DeveloperOpen

• Encode HTML entities

  Escape <, >, & and quotes for HTML, and optionally every non-ASCII character. DeveloperOpen

• Decode HTML entities

  Turn &amp;, &eacute; and &#169; back into normal characters. DeveloperOpen

• Generate UUIDs

  Make random (v4) or time-ordered (v7) UUIDs, one or thousands, and inspect a UUID. DeveloperOpen

• Convert Unix timestamps

  Unix time to a date and back, in seconds or milliseconds, in any time zone. DeveloperOpen

• Make meta tags

  Write the title, description, Open Graph and Twitter tags for a web page, with previews. DeveloperOpen

• Make a CSS gradient

  Design linear, radial and conic gradients and copy the CSS. DeveloperOpen

• Make a CSS box shadow

  Design layered box shadows with a live preview and copy the CSS. DeveloperOpen

• Format and check YAML

  Re-indent and check YAML with exact error lines, keeping its comments. DeveloperOpen

• Convert YAML and JSON

  Turn YAML into JSON and JSON into YAML, multi-document files included. DeveloperOpen

• Format and check TOML

  Check and tidy TOML keeping comments, and convert TOML to and from JSON. DeveloperOpen

• Format SQL

  Make SQL queries readable, for PostgreSQL, MySQL, SQL Server, Oracle and more. DeveloperOpen

• Make TypeScript, Go or a schema from JSON

  Generate TypeScript interfaces, Go structs or a JSON Schema from example JSON. DeveloperOpen

• Compare two JSON files

  See what was added, removed or changed between two JSON documents, by path. DeveloperOpen

• Split a URL into parts

  See a URL's host, path, query parameters and fragment, and edit the parameters. DeveloperOpen

• Build a campaign link (UTM)

  Add utm_source, utm_medium and utm_campaign to links for Google Analytics. DeveloperOpen

• Write or explain a cron schedule

  Build cron schedules, read them in plain English and see the next run times. DeveloperOpen

• Look up an HTTP status code

  What every HTTP status code means and what to do about it: 404, 500, 502, 429… DeveloperOpen

• Find a MIME type

  Find the MIME type (Content-Type) for a file extension, or the extension for a type. DeveloperOpen

• Calculate an IP subnet

  Network, broadcast, host range and mask for IPv4 and IPv6 CIDR blocks, and subnet splitting. DeveloperOpen

• Work out Unix permissions

  Convert file permissions between checkboxes, octal (755) and rwxr-xr-x, with the chmod command. DeveloperOpen

• Read a User-Agent string

  See the browser, system, device or bot behind a User-Agent, one or many from a log. DeveloperOpen

• Generate a secret key or token

  Random API keys, secrets and tokens in hex, Base64 or letters, with their strength in bits. DeveloperOpen

• Hash a text (MD5, SHA-256)

  MD5, SHA-1, SHA-256, SHA-512, SHA-3, BLAKE3 and CRC32 of a text, and HMAC signatures. DeveloperOpen

Quick conversions

One-click versions of the converters with the format already chosen.

• JSON to YAML
• JSON to TypeScript
• JSON to Go struct
• JSON Schema from JSON

About these tools

Pasting a token, an API response or configuration into an online tool usually sends it to someone else's server. Here everything runs in the page: the security policy blocks the page from uploading anything, so even secrets you paste stay on your device.

The formatters only change whitespace and layout, never what your code does. The regex tester uses your browser's own JavaScript regular expression engine, so results match what your JavaScript code will do.

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