About FormatKit

Every tool does one job and shows its result on the page you landed on — no wizard, no tab to click first, no “upload and wait”. They fall into 10 groups:

• Format & beautify (7) — JSON Formatter, Prettify JSON, SQL Formatter, HTML Formatter, YAML Formatter, JavaScript Formatter, CSS Formatter.
• View & edit (4) — JSON Viewer, JSON Editor, XML Viewer, CSV Viewer.
• Encode & decode (9) — Base64 Decode, URL Decode, Base64 Encode, URL Encode, Image To Base64, Base64 To PDF, Escape JSON, HTML Encode, File To Base64.
• Compare (5) — Text Compare, Diff Checker, Compare JSON, JSON Diff, Code Diff.
• Dev utilities (10) — Lorem Ipsum Generator, Epoch Converter, Hex To Decimal, UUID Generator, Unix Timestamp, JWT Decoder, Regex Tester, Decimal To Binary, Timestamp Converter, Cron Expression Generator.
• Markdown (7) — Markdown Editor, Markdown Preview, PDF To Markdown, Markdown To HTML, Markdown Table Generator, Table Generator, HTML To Markdown.
• Validate (5) — XML Validator, JSON To JSON Schema, YAML Validator, JSON Checker, JSON Schema Validator.
• Convert (10) — CSV To Excel, XML To JSON, CSV To JSON, Excel To CSV, JSON To Excel, XML To CSV, YAML To JSON, JSON To YAML, JSON To XML, Excel To JSON.
• Reference (5) — ASCII Table, HTTP Status Codes, User Agent Parser, cURL Converter, URL Parser.
• Minify (3) — Minify JavaScript, Minify JSON, Minify CSS.

The catalogue on the home page lists all of them with a line each about what they actually do.

Because the work rarely stops at one operation. You decode a JWT and immediately want its payload indented; you flatten a CSV and then need the result as a Markdown table; you fix a config file and then minify it. Splitting those steps across separate domains means a new page load, a new interface and a new set of quirks each time, which is why this is a hub: the next tool is one link away and behaves exactly like the last one.

It also keeps the tools honest. A shared frame means every page has the same anatomy — the tool at the top, a how-to, a specification table with real numbers, questions people actually ask, and links to the neighbours. What is deliberately not shared is the writing: each page is written for its own operation, because a page that could be find-and-replaced into another one is worth nothing to the person reading it.

The site is a static export: every page is plain HTML generated ahead of time and served from a CDN, with no application server anywhere in the request. Each tool is a small JavaScript program that your browser downloads once and then runs locally, so the round trip that most online converters spend on an upload simply does not happen — results appear in the same frame you typed in.

The parsing is written for these pages rather than pulled from a library, which buys two things worth having. Errors carry a position, so a broken document gets line 14, column 7 and the character at fault rather than a bare “parse error”. And the source text survives: number literals, key order and the escapes you wrote are preserved instead of being normalised into whatever a generic parser happens to emit. Documents up to 5 MB are accepted, which covers the overwhelming majority of API responses, exports and config files people paste in.

Three queries that neighbour this catalogue are handled by separate sites we also run, rather than duplicated here: format-xml.com for XML beautifying, json-to-csv.app for JSON-to-spreadsheet conversion, and html-to-txt.com for stripping markup out of text.

Whatever you paste stays in the tab. There is no endpoint to send it to, nothing is written to storage on your device, and closing the tab is the whole of the clean-up. The practical proof is that the tools keep working with the network disconnected: if a document had to reach a server, they could not.

What the site does load from elsewhere is ordinary web furniture — advertising and anonymous page-view counts — and those see the address of the page, never its contents. It is worth being precise about the boundary: this describes what FormatKit does with your data, and says nothing about a browser extension, a corporate proxy or the machine itself.