Free, local, no account
Developer tools for exact work—not generated guesses.
Fuccura’s free developer toolbox handles the small but repetitive tasks behind debugging, APIs, configuration, and data checks. Format a JSON payload, decode a JWT, create a UUID, test a regular expression, or convert a Unix timestamp in seconds—without creating an account or sending your input to our server.
JSON formatter, minifier & validator
Format API payloads, validate syntax, or create compact JSON without leaving the browser.
Paste JSON, then format, minify, or validate it.
What this page does
Reliable utilities for the parts of development that must be precise.
AI can help explain code, but it should not be the source of truth for deterministic conversions, security-adjacent inspection, or structured-data validation. These tools use browser APIs and standard transformations, so the same input produces the same result every time.
Frequently asked questions
Clear answers before you paste anything.
Are these developer tools free?
Yes. The tools on this page are free to use and do not require an account.
Are API payloads or JWTs uploaded?
No. Transformations, decoding, formatting, and testing run in the browser on your device.
Does the JWT decoder verify a token?
No. It decodes the public header and payload for inspection. Signature verification requires the signing key or a trusted identity provider.
Can I run code or compile a project here?
This page intentionally avoids executing arbitrary code. It provides safe, deterministic tools that work instantly in the browser.