Developer Tools

Everyday utilities for writing and debugging code: JSON formatting, Base64 encoding, and more, all running client-side with nothing sent to a server.

Image to Base64 Converter

Convert an image into a Base64 data URL for HTML or CSS.

Paste a Base64 string or data URL to preview and download it as an image.

Convert between TTF, OTF, WOFF, and WOFF2 font formats.

Pretty-print, minify, and validate JSON, with the exact parse error if it's invalid.

Indent and lay out a SQL query consistently, across MySQL, PostgreSQL, T-SQL, and more.

Encode text to Base64 or decode a Base64 string back to plain text.

Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes of text or a file.

Decode a JSON Web Token's header and payload without verifying the signature.

Convert between YAML and JSON, in either direction.

Encode text for safe use in a URL, or decode a URL-encoded string.

Convert between Unix epoch time and human-readable dates.

Convert a number between binary, octal, decimal, and hexadecimal.

The mistakes behind most "invalid JSON" errors, with before-and-after fixes and how to read where the parser gave up.

What the three parts of a JWT hold, what decoding does and doesn't prove, and how to read expiry claims safely.

Related tool: JWT Decoder

Seconds versus milliseconds, UTC versus local time, and the year 2038 limit, plus the mistakes that produce wrong dates.

How Base64 works, why it adds about a third to the size, why it isn't encryption, and how Base64URL differs.