Free File & Data Tools

9 developer-grade utilities for JSON, XML, SQL, YAML, JWTs, Base64 and files

Data rarely arrives in the shape you need it: JSON comes minified into one unreadable line, tokens are opaque Base64 blobs, SQL queries lose their structure in logs, and someone always emails a file in the wrong format. This category is the toolbox for those moments — formatters, converters and inspectors that make data legible and portable.

These tools are built for developers but need no setup: everything runs in the browser, which also means API responses, tokens and queries you paste stay on your machine. That's especially important for JWTs and production data — decoding here doesn't leak anything to a third-party server.

All File & Data Tools at a Glance

What Each Tool Does

Every tool below opens instantly, needs no account, and processes your data locally in your browser. Here is what each one is for:

Image to Base64

Convert images into Base64 data URIs (and back) for embedding in CSS, HTML or JSON without separate files. Open the Image to Base64 →

File Size

See a file's exact size in bytes, KB, MB and GB — no more guessing what 'about 5 MB' means. Open the File Size →

JSON Formatter

Pretty-print, validate and minify JSON with error positions — the daily driver for anyone reading API responses. Open the JSON Formatter →

Format Converter

Convert files between common formats — images, audio, documents and data — right in the browser. Open the Format Converter →

Unicode Analyzer

Inspect every character in a string with its Unicode name and code point — the fastest way to find invisible or lookalike characters. Open the Unicode Analyzer →

XML Formatter

Format and indent XML for reading, or minify it for transport, with syntax checking. Open the XML Formatter →

YAML Converter

Convert YAML to JSON and back — reconcile config files and API payloads in one paste. Open the YAML Converter →

SQL Formatter

Turn single-line SQL into properly indented, readable queries — ideal for reviewing ORM output and logs. Open the SQL Formatter →

JWT Decoder

Decode JSON Web Tokens into header and payload locally — inspect claims and expiry without sending the token anywhere. Open the JWT Decoder →

How to Choose the Right Tool

The JSON Formatter pretty-prints, validates and minifies JSON — probably the most-reached-for tool here. XML and SQL Formatters do the same for their languages, and the YAML Converter translates between YAML and JSON. The JWT Decoder splits a token into header, payload and signature so you can inspect claims safely offline. Image to Base64 embeds images as data URIs; the Unicode Analyzer names every character in a string (great for hunting invisible characters); the File Size Checker reports exact byte sizes; and the Format Converter moves data between common file formats.

Frequently Asked Questions

Is it safe to paste API responses and tokens here?

Yes — everything is parsed locally in your browser. Nothing you paste is transmitted, which is exactly why local tools are recommended for JWTs.

Does the JSON formatter validate syntax?

Yes — it reports parse errors with position information, then formats or minifies valid JSON.

Can the JWT decoder verify signatures?

It decodes and displays header and payload; signature verification requires the signing key and is out of scope for an offline inspector.

What's the largest file or text these tools handle?

They comfortably handle multi-megabyte inputs; the practical ceiling is your device's memory since processing is local.

Explore More WiserWork Categories

WiserWork offers 295 free browser-based tools across 22 categories — all private, all free, no sign-up required.