Data Formatters & Converters

Format, validate and convert the data and configuration formats developers handle every day: JSON, YAML, XML, CSV, TOML and .env files. Every tool here keeps the same information and changes only its structure — pretty-printed for reading, minified for shipping, or converted for the next system. Everything runs in your browser, so API responses and customer records never leave your machine.

Format

Action

JSON Formatter
Pretty-print, validate and minify JSON.
JSON
JSON Validator
Check JSON and see exactly where and why it breaks.
JSON
YAML Formatter
Format and validate YAML with exact error locations.
YAML
XML Formatter
Pretty-print, validate and minify XML.
XML
JSON to YAML
Convert JSON to clean, readable YAML.
JSONto YAML
YAML to JSON
Convert YAML to formatted JSON.
YAMLto JSON
JSON to CSV
Flatten JSON arrays into CSV for spreadsheets.
JSONto CSV
CSV to JSON
Turn CSV rows into a JSON array.
CSVto JSON
XML to JSON
Convert XML payloads to JSON.
XMLto JSON
JSON Minifier
Compact JSON to a single line.
JSON
JSON Escape / Unescape
Turn JSON into a string literal and back.
JSONto Text
TOML Formatter
Format and validate TOML config files.
TOML
JSON to TOML
Convert JSON objects to TOML.
JSONto TOML
TOML to JSON
Convert TOML config to JSON.
TOMLto JSON
CSV Viewer & Formatter
View CSV as a table and normalize delimiters and quoting.
CSV
URL Parser & Formatter
Break a URL into parts and pretty-print its query string.
URLto JSON
JSON to XML
Convert JSON to well-formed XML.
JSONto XML
TSV to CSV
Convert tab-separated values to CSV and back.
TSVto CSV
.env Formatter
Normalize and validate .env files.
.env

Common tasks

About data tools

Data tools are the heart of Formattr. Most payloads a developer sees in a day are one of these formats: a JSON response from an API, a YAML manifest for Kubernetes or GitHub Actions, an XML document from a legacy SOAP service or an RSS feed, a CSV export from a dashboard, or a TOML file that configures a Rust or Python project. The job is almost always the same — make it readable, find what is broken, or turn it into the shape another system expects.

Each formatter validates as it formats. When input is invalid you get the exact line and column, the likely cause in plain language, and — for the common breakages like trailing commas, single quotes or unquoted keys — a one-click fix. Conversions keep round-trips honest: JSON to YAML and back produces the same data, and CSV conversions let you choose delimiters, headers and how nested objects are flattened into columns.

Tools are chained. After formatting JSON you can convert it to YAML, CSV or XML with one click, and a breadcrumb takes you back through each step without re-pasting anything.

Frequently asked questions

Is my data uploaded when I format it?

No. Formatting, validation and conversion run inside an isolated frame in your browser that blocks outgoing network requests. You can confirm this in your browser’s developer tools: the Network tab shows no requests while you format.

How large a file can I format?

Up to 50 MB. Above 1 MB auto-format pauses and you press Format; larger inputs run in a background worker so the page stays responsive.

Do conversions lose information?

JSON, YAML and TOML convert losslessly for data types they share. CSV is flat, so nested objects are flattened into dotted column names and can be rebuilt when converting back. XML attributes are kept with a configurable prefix.

Can I keep my settings?

Yes. Indent, sort order and other options are remembered per tool on this device, and can be shared as a link that carries settings but never content.