File & Data Converters

Convert between CSV, JSON, YAML, XML and Markdown, open a file, convert, download the result. Exports and configs are business data: here they never touch a server, and there are no size limits or paid tiers.

JSON Formatter & Validator Paste or open any JSON, get it pretty-printed or minified, with validation errors pinpointed to the exact line and column.
CSV to JSON Converter Paste or open a CSV and get JSON records instantly, headers become keys, numbers and booleans stay typed, and the delimiter is auto-detected.
JSON to CSV Converter Paste a JSON array of objects and get spreadsheet-ready CSV, headers from the union of all keys, quoting handled correctly.
JSON to YAML Converter Paste JSON, get equivalent YAML, the format Kubernetes, GitHub Actions and docker-compose expect.
YAML to JSON Converter Paste YAML, a Kubernetes manifest, CI config, front-matter, and get exact JSON, with YAML errors explained.
XML to JSON Converter Paste XML and get JSON, attributes keep an @ prefix, repeated sibling elements become arrays, and parse errors are reported plainly.
JSON to XML Converter Paste JSON and get well-formed XML, object keys become elements, arrays repeat their tag, and you choose the root name.
CSV to Markdown Table Paste CSV, copy a Markdown table, ready for GitHub READMEs, pull requests, and any docs that speak Markdown.
Markdown to HTML Converter Paste Markdown, get the HTML it renders to, headings, lists, links, tables and code blocks included.
E-Invoice Viewer (XRechnung / ZUGFeRD) Received an XML invoice you can't read? See the seller, amounts, line items and payment details instantly, parsed on your device, because invoices are exactly the data not to upload.
Factur-X Viewer (French E-Invoice) France's e-invoicing mandate starts 1 September 2026, and Factur-X is its flagship format: a normal-looking PDF with the legal invoice data embedded as XML inside. This viewer extracts and shows that data, including which Factur-X profile the invoice uses, without your invoice leaving the browser.
KSeF Invoice Viewer (Poland FA(3)) Read a faktura ustrukturyzowana without any software, since April 2026 every VAT-registered business in Poland invoices through KSeF, and what lands in your systems is FA(3) XML. This viewer turns it back into a readable invoice, entirely in your browser.
KSeF Invoice Pre-Checker (FA(3)) Catch the obvious rejections before KSeF does, structure, required fields and NIP check digits, verified locally in seconds. Unofficial by design: only KSeF acceptance is legal validation.
Peppol BIS Invoice Viewer (Belgium) Belgium's B2B e-invoicing mandate has been live since 1 January 2026, exchanged over the Peppol network as UBL XML. This viewer reads those files as a normal invoice, entirely in your browser.
Excel to CSV Converter Turn an .xlsx or .xls workbook into plain CSV, choose the sheet and download, all on your device.
Excel to JSON Converter Turn a spreadsheet into an array of JSON objects, keyed by the header row, pick the sheet, copy or download, locally.
CSV to Excel Converter Turn CSV text or a .csv file into a proper .xlsx spreadsheet that opens cleanly in Excel, all on your device.
TOML to JSON Converter Paste TOML (like a Cargo.toml or pyproject.toml) and get equivalent JSON, parsed locally on your device.
JSON to TOML Converter Paste JSON and get equivalent TOML for a config file, serialised locally, nothing uploaded.
XML Formatter & Minifier Paste messy or minified XML to format it with clean indentation, or minify it, all on your device.
HTML to Markdown Converter Paste HTML and get clean Markdown, headings, links, lists, bold and code all converted, locally.
JSONL to JSON Converter JSONL puts one JSON value per line. This wraps those lines into a single JSON array you can use anywhere, reporting the exact line of any parse error.
JSON to JSONL Converter Turn a JSON array into JSONL: each element becomes one line of compact JSON, the format streaming tools and ML pipelines expect.
INI to JSON Converter Paste an INI file and get JSON: each [section] becomes a nested object and every key=value becomes a string property.
JSON to INI Converter Paste a JSON object and get an INI file: scalar properties go at the top and each nested object becomes a [section].
.env to JSON Converter Paste a .env file and get JSON: each KEY=value line becomes a property, with quotes, export and comments handled.
JSON to .env Converter Paste a JSON object and get a .env file: each property becomes a KEY=value line, quoted when it needs to be.
Java .properties to JSON Converter Paste a Java .properties file and get a flat JSON object, with continuations, escapes and : separators handled correctly.
JSON to Java .properties Converter Paste a JSON object and get a Java .properties file, with separators, spaces and special characters properly escaped.
File to Base64 Encoder Turn any file into Base64 text, or a full data URI you can paste straight into CSS or HTML, encoded locally, never uploaded.
Base64 to File Decoder Paste Base64 text or a full data URI and get the original file back as a download, decoded locally, never uploaded.
GPX Analyzer (Elevation & Pace) Open a GPX track and get its distance, elevation gain/loss, duration, average speed and pace, all calculated locally, so your locations stay private.
GPX to GeoJSON Converter Paste or open a GPX file and get GeoJSON, the track as a LineString and waypoints as Points, in [lon, lat] order for web maps.
GeoJSON to GPX Converter Paste GeoJSON and get a GPX 1.1 file, LineStrings become tracks and Points become waypoints, ready to load onto a GPS device.
vCard (VCF) to CSV Converter Paste or open a .vcf file and get a clean CSV of your contacts, one row each, with name, email, phone and organization columns.
CSV to vCard (VCF) Converter Paste or open a CSV of contacts and get a .vcf file, one vCard per row, that imports straight into your phone or address book.
SVG Optimizer & Minifier Paste or open an SVG and get a smaller, cleaner version, editor junk, comments and metadata removed and whitespace collapsed, with the image unchanged.
ZIP Extractor (Open ZIP Online) Open a .zip to list its contents and pull out any file, right in your browser, with no software to install and nothing uploaded.
Create ZIP (Zip Files Online) Add your files and download them as one .zip, built entirely in your browser, so nothing is uploaded.
EPUB Metadata Viewer Drop an .epub to read its title, author, series, publisher, ISBN, language, subjects and description, parsed locally from the book.
Torrent File Viewer (Info-Hash) Drop a .torrent to read what's inside it, files, size, piece length, trackers, and compute its info-hash and magnet link, all locally.
Google Polyline Encoder / Decoder Decode a Google Maps polyline string into coordinates (and GeoJSON), or encode a list of lat/lng points into one, with precision 5 or 6.
MP4 / MOV Box (Atom) Viewer Drop an MP4/MOV/M4A file to see its internal box (atom) tree, brand, duration and track types, the fast way to see why a video won't play.
WKT to GeoJSON Converter Paste a WKT geometry like POINT (30 10) or POLYGON ((…)) and get equivalent GeoJSON, parsed locally on your device.
GeoJSON to WKT Converter Paste a GeoJSON geometry (or Feature) and get OGC WKT like POLYGON ((…)), ready for PostGIS or a spatial query, converted locally.

Convert data without uploading it

Moving structured data between formats, CSV, JSON, XML, YAML and Markdown, is a routine chore that most online converters do by uploading your file to a server. These do it in your browser instead, parsing and re-serialising locally so the conversion is instant and your data never leaves the page. Delimiters, nesting and types are preserved, and you can paste or drop a file either way.

That matters when the "data" is a customer export, a financial extract or an internal config: there's no server to receive it, cache it or leak it. Round-trip a file to check it survives, and everything works offline once loaded.

Frequently asked questions

Are my files uploaded to convert them?

No, the "Open file" button reads the file into your browser's memory only. Parsing and conversion run locally, nothing is transmitted, and the tools work offline. Business data, configs and exports stay on your machine.

Is there a file-size limit or paid tier?

Neither. Because conversion is local there are no upload caps, multi-megabyte exports convert instantly, free. (Several competitor tools cap free conversions at 1 MB per day.)

How accurate are the conversions?

CSV parsing follows RFC 4180 conventions (quoted fields, escaped quotes); YAML uses js-yaml, the standard library; XML uses the browser's native parser; Markdown uses marked with GitHub-flavored extensions. Errors are reported with line locations rather than silently producing wrong output.