Free File & Data Tools

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 →

JSON Stringifier

Escape JSON into a quoted, embeddable string — the opposite job of the JSON Formatter, useful for nesting JSON inside JSON or code. Open the JSON Stringifier →

JSON to Text Converter

Flatten JSON into a readable, indented plain-text report — key: value lines instead of braces and quotes. Open the JSON to Text Converter →

Unicode to UTF-8 Converter

See the exact UTF-8 byte encoding of any text, as hex bytes or \xNN escapes, straight from TextEncoder. Open the Unicode to UTF-8 Converter →

Hex to UTF-8 Converter

Paste space-separated hex bytes and decode them back to text, with a clear error for malformed UTF-8. Open the Hex to UTF-8 Converter →

UTF-8 Validator

Check whether hex bytes or a file are well-formed UTF-8, with the exact byte offset of the first problem. Open the UTF-8 Validator →

Unicode to Hex Converter

See the U+XXXX Unicode code point of every character in your text, correctly handling emoji and surrogate pairs. Open the Unicode to Hex Converter →

Text to CSV Converter

Turn freeform comma, tab or pipe-delimited text into clean, properly quoted CSV. Open the Text to CSV Converter →

How to Choose the Right Tool

The JSON Formatter pretty-prints, validates and minifies JSON — probably the most-reached-for tool here. When you need JSON as an embeddable string instead, the JSON Stringifier escapes it; when you need it as a human report instead of syntax, the JSON to Text Converter flattens it. XML and SQL Formatters do the same beautifying job 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. For encoding questions, the Unicode Analyzer inspects one character in depth, Unicode to Hex lists code points across a whole string, Unicode to UTF-8 shows the byte encoding, Hex to UTF-8 decodes bytes back to text, and the UTF-8 Validator pinpoints the first malformed byte. Image to Base64 embeds images as data URIs; the File Size Checker reports exact byte sizes; the Format Converter moves data between common file formats; and the Text to CSV Converter cleans up delimited text into standards-compliant CSV.

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 423 free browser-based tools across 26 categories — all private, all free, no sign-up required.