Developer Tool Collection
Free Developer Tools for JSON, YAML, APIs and Code
Format, validate, encode, decode, inspect and generate common developer data directly in your browser. Use focused tools for API debugging, backend development, DevOps configuration, code cleanup and test-data preparation.
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Popular developer tools
40 curated utilities
JSON Studio
Format, validate, compare, view, split, merge and analyse JSON in one browser-based workspace.
YAML Studio
Create and inspect YAML for Kubernetes, Docker Compose, GitHub Actions, Azure DevOps and other configuration workflows.
JWT Decoder
Inspect JWT headers, payloads, claims and expiry information without writing a temporary decoding script.
HTTP Header Parser
Parse raw request or response headers into a readable structure for API and web debugging.
JSON and structured-data tools
Format JSON online, validate syntax, compare payloads, test JSONPath expressions and generate schemas or C# models. These tools are practical for API responses, ERP integrations, ePOS data, logs and nested application payloads.
JSON Studio
Advanced JSON workspace.
JSON Formatter
Beautify compact or messy JSON.
JSON Validator
Check JSON syntax and errors.
JSON Viewer
Explore JSON in a readable view.
JSON Compare
Compare two JSON documents.
JSON Minifier
Remove unnecessary JSON whitespace.
JSON Schema Generator
Create a schema from sample JSON.
JSONPath Explorer
Test JSONPath expressions.
JSON to C#
Generate C# models from JSON.
YAML, XML and configuration tools
Prepare readable configuration files, validate indentation and compare changes before copying output into Kubernetes, CI/CD or application configuration workflows.
YAML Studio
Work with YAML and common DevOps templates.
YAML Formatter
Clean and format YAML.
YAML Validator
Check YAML syntax and indentation.
YAML Compare
Compare two YAML documents.
Kubernetes YAML Generator
Build starter Kubernetes manifests.
XML Formatter
Beautify XML markup.
XML Validator
Check whether XML is well formed.
API, encoding and security utilities
Decode JWT and Base64 values, inspect URLs and HTTP headers, look up MIME types and generate safe test values. Never paste production secrets, private keys or live credentials into an online tool.
JWT Decoder
Inspect JWT claims and expiry data.
Base64 Encoder
Encode text as Base64.
Base64 Decoder
Decode Base64 values.
URL Encoder
Encode URL and query-string characters.
URL Decoder
Decode percent-encoded URLs.
URL Parser & Analyzer
Inspect URL components and parameters.
HTTP Header Parser
Parse raw HTTP headers.
HTTP Headers Checker
Review response and security headers.
MIME Type Lookup
Find common MIME types and extensions.
Hash Generator
Generate hashes for development checks.
Password Generator
Create configurable random passwords.
Code formatting, testing and generators
Clean SQL, HTML, CSS and JavaScript snippets, test regex patterns, understand cron schedules and create identifiers or mock data for development and QA work.
Regex Tester
Test regular expressions against sample text.
SQL Formatter
Format SQL queries for easier review.
SQL Minifier
Compact SQL by removing extra whitespace.
HTML Formatter
Beautify HTML markup.
HTML Minifier
Reduce HTML size.
CSS Formatter
Format CSS rules.
CSS Minifier
Compress CSS source.
JavaScript Formatter
Beautify JavaScript code.
JavaScript Minifier
Compact JavaScript source.
Cron Parser
Explain cron expressions and schedules.
UUID Generator
Generate UUID values for testing.
MAC Address Generator
Generate sample MAC addresses.
API Mock Generator
Create sample API response data.
Common developer workflows
Inspect authentication data
Prepare configuration files
Browser-based developer tools and privacy
Browser tools are useful for quick formatting, debugging and documentation tasks because they remove the need to create a temporary project or install a separate extension. They are especially convenient during code review, support work and API troubleshooting.
Even when processing happens locally, use sample or sanitised data whenever possible. Generated schemas, configuration files, passwords, hashes and code should be reviewed and tested with official project libraries before production use.
Frequently asked questions
What are online developer tools?
Online developer tools are focused browser utilities for formatting, validating, encoding, decoding, generating and inspecting technical data without setting up a local script or IDE extension.
Which tools are useful for API debugging?
JSON Formatter, JSON Validator, JSONPath Explorer, JWT Decoder, Base64 Decoder, URL Parser, HTTP Header Parser and JSON Schema Generator are useful for investigating API requests and responses.
Can I use these tools for JSON and YAML configuration files?
Yes. FormatForge includes dedicated JSON and YAML formatting, validation, comparison and generation tools, including JSON Studio, YAML Studio and a Kubernetes YAML Generator.
Do FormatForge developer tools upload my data?
Many of these utilities process text directly in the browser. Still, avoid entering production secrets, private keys, credentials or confidential tokens into any online utility.
Can I use generated output directly in production?
Treat generated code, schemas, hashes, passwords and configuration files as starting points. Review and test the output with your project's official libraries, security controls and deployment process before production use.
Are these developer tools free?
Yes. The developer tools in this collection are available free of charge and can be opened individually without creating an account.
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Choose with confidence
How to use Developer Tools effectively
Start with the outcome you need, use the smallest suitable tool, and verify the downloaded or copied result before relying on it. The guidance below helps turn individual utilities into a reliable workflow.
Frontend and backend developers
QA engineers checking payloads
Students learning APIs and structured data
Start here
Pick the right first step
01
Inspect structured data
Format and validate JSON before debugging downstream code.
Open recommended tool →02
Work with configuration
Use YAML Studio for readable configuration and syntax checks.
Open recommended tool →03
Test smaller values
Decode tokens, test regular expressions or format SQL in focused utilities.
Open recommended tool →Before you finish
Quality-check the result
- ✓Remove secrets before pasting examples
- ✓Validate output in the destination system
- ✓Keep source and converted copies
- ✓Do not treat decoded tokens as verified tokens
Recommended workflows
Complete the task, not just one conversion
Debug an API payload
- 1Format the response
- 2Validate its syntax
- 3Inspect nested paths
- 4Convert only after the source is correct
Review configuration
- 1Paste a safe sample
- 2Validate indentation and structure
- 3Compare the generated output
- 4Test in the target environment
Continue your workflow