API tools
HTTP status codes, headers, URLs, query strings, JSON testers, cURL generator, and cURL converters
Need a tool that is not on this list? Open Contact Us and describe the job in detail: the input you have, the result you want, and how the tool should work.
HTTP Status Code Lookup
Look up HTTP status codes and what they mean
HTTP Headers Viewer
Parse raw HTTP request or response headers
URL Parser
Split a URL into host, path, query, and hash
Query String Parser
Decode query parameters into a table and JSON
JSON API Tester
Send JSON requests and pretty-print JSON responses
cURL Generator
Build a cURL command from URL, token, headers, and body
cURL to Java
Convert a cURL command to Java HttpClient code
cURL to JavaScript
Convert a cURL command to fetch() JavaScript
cURL to Python
Convert a cURL command to Python requests code
cURL to PHP
Convert a cURL command to PHP curl_init code
cURL to C#
Convert a cURL command to C# HttpClient code
cURL to Go
Convert a cURL command to Go net/http code
About Free Tool Mate
Free Tool Mate is a free online toolkit of browser based developer utilities for JSON, XML, SQL, YAML, text, images, PDFs, encoding, generators, and everyday calculations. Format and validate JSON, beautify SQL queries, convert XML to JSON, decode Base64 and JWT tokens, generate UUIDs and strong passwords, resize images, protect PDF files, and create printable receipts without installing software. Every tool runs entirely in your browser, so your data is never uploaded to a server. There is no sign-up, no account, and no usage cap.
Developers, testers, writers, students, and office teams use Free Tool Mate when they need a fast private workspace. Paste an API payload, open a PDF, drop a photo, or type a query and get an instant result you can copy, print, or download. Related tools sit next to each other so you can move from formatting to comparing to converting in a few clicks. The homepage filter pills jump you straight into JSON, SQL, Image, PDF, Text, or Calculators.
The catalog covers a JSON viewer, JSON beautifier, JSON compare and JSON diff, JSON Schema validator, JSONPath tester, XML formatter, XML to JSON converter, SQL formatter, SQL beautifier, SQL validator, YAML tools, Base64 encoder, URL encoder, hash generator, regex tester, timestamp and epoch converters, date and age calculators, a percentage calculator, a unit converter, image converter and resizer, a PDF editor, PDF merge, PDF split, PDF compress, PDF password protection, PDF unlock, and receipt generators. Search engines can read this page as a hub for free online developer tools.
Because processing is local, sensitive logs, access tokens, contracts, salary slips, and photos never leave your device. Bookmark the homepage and return whenever you need a free JSON formatter, SQL validator, PDF editor, image converter, or text counter. If you need a tool that is not listed yet, open Contact Us and describe the job in detail so we can consider adding it. Free Tool Mate is built to be useful every day: quick, private, and ready in the browser you already have.