Can I paste API responses safely?
The tools process input locally in your browser, which reduces exposure compared with server-side tools. Do not paste production secrets into any tool unless your own policy allows it.
Developer & Code
Developer Tools That Run Locally
Debug, format, encode, and inspect common developer data formats directly in the browser. These tools are useful for API debugging, documentation, test data, and safe handling of internal snippets.
Quick Answers
Which tool validates JSON?
Use JSON Formatter for syntax validation, formatting, and minification. Use schema validation separately for API contract rules.
Can the JWT Decoder verify signatures?
The JWT Decoder is for inspecting token headers and payloads. Signature verification requires the correct secret or public key.
Tools in this category
JSON Formatter & Validator Format, minify, and validate JSON syntax. Base64 Encoder & Decoder Convert text to and from Base64. Code Minifier Minify HTML, CSS, and JavaScript snippets. URL Encoder & Decoder Encode and decode URL-safe strings. Hash Generator Generate SHA-1 and SHA-256 hashes locally. RegEx Tester Test regular expressions against sample text. JWT Decoder Inspect JWT headers and payloads. CRON Expression Descriptor Translate cron expressions into readable schedules. CSV ↔ JSON Converter Convert data between CSV and JSON formats. JWT Encoder & Decoder Encode and sign JWTs with HS256, or decode tokens. Timezone Converter Convert time between any two timezones. JSON ↔ XML Converter Convert data between JSON and XML formats. JSON ↔ YAML Converter Convert data between JSON and YAML formats. JSONPath Tester Query JSON data using JSONPath expressions. Meta Tag Generator Generate HTML meta tags for SEO. Open Graph Preview Preview how pages look when shared on social media. Schema.org Generator Generate JSON-LD structured data markup. robots.txt Generator Create robots.txt files for crawler control. Business Day Calculator Add or count business days between dates. Countdown Timer Set a live countdown to any date and time. Age Calculator Calculate exact age in years, months, and days.
How to use these tools well
- Local processing helps with privacy but does not replace secure handling policies.
- Validate production data against schemas and tests.
- Never expose live secrets in screenshots or shared outputs.