Free tools that never upload your data

49 PDF, developer, text, and everyday tools — running entirely in your browser. No server, no sign-up, no one but you ever sees your files.

100% client-side — verifiable in DevTools, works offline

PDF tools

16 tools

Developer tools

25 tools

Format & validate

JSON FormatterPretty-print, minify, and validate JSON with exact error positions.Regex TesterLive match highlighting and capture groups (JavaScript flavor).Cron ParserPlain-English explanations and the next five run times.Markdown PreviewLive GitHub-style rendering, sanitized on your device.SQL FormatterPretty-print queries in five dialects.HTML/CSS/JS FormatterBeautify or minify — with the real Terser for JS.WCAG Contrast CheckerAA/AAA verdicts with a live text preview.

Encode & decode

JWT DecoderDecode and verify tokens — they never leave your browser.Base64 Encode/DecodeText and files, standard or URL-safe, fully UTF-8 aware.URL Encoder/DecoderPercent-encode query values or decode messy URLs.HTML EntitiesEscape markup or decode entities back to readable text.Number Base ConverterBinary, octal, decimal, hex — exact BigInt conversion.JSON ↔ YAML ↔ TOMLConvert configs between formats, live and locally..env ↔ JSONEnvironment files to JSON and back — secrets stay local.curl → fetch/axiosPaste a curl command, get ready-to-use JavaScript.

Generators

Hash GeneratorMD5 and SHA hashes of text or files via WebCrypto.UUID / ULID / Nano IDUUID v4/v7, ULID, and Nano ID in bulk from crypto randomness.QR Code Generator & ReaderGenerate PNG/SVG codes or decode one from an image.Password GeneratorCrypto-random passwords with an honest entropy meter.Lorem IpsumPlaceholder words, sentences, and paragraphs.Mock Data GeneratorFake names, emails, and JSON records for testing.

Text & time

Timestamp ConverterUnix epoch to human time and back, with live current time.Case ConvertercamelCase, snake_case, kebab-case, and friends — all at once.Diff CheckerCompare two texts line-by-line or word-by-word.Color ConverterHEX, RGB, HSL, and OKLCH with a live swatch.

Text & data

4 tools

Word CounterWords, characters, sentences, and reading time — live.Text Sorter & DedupeSort, dedupe, trim, shuffle, and reverse lines.CSV ↔ JSONSpreadsheet exports to JSON and back, with a preview table.Slug GeneratorURL-friendly slugs, diacritics handled.

Everyday tools

4 tools

Unit ConverterLength, weight, temperature, data sizes, and more.Percentage CalculatorX% of Y, what percent, and percent change.Image Resize & ConvertLive before/after preview — AVIF, WebP, JPG, PNG via WASM codecs.Stopwatch & PomodoroStopwatch with laps, countdown, and Pomodoro focus.

Why files stay private here

No backend

This is a static site. There is no server that could receive, store, or log your documents.

Enforced by the browser

A strict Content-Security-Policy blocks the app from sending data to third parties — the browser enforces it, not our goodwill.

Verifiable

Open DevTools → Network while you work: zero requests with your data. It even works with the internet disconnected.

Frequently asked questions

Are my files uploaded to a server?

No. KeepItLocally has no backend at all — it is a static site. Every operation (PDFs, images, JSON, tokens) runs inside your browser using WebAssembly and JavaScript. Your data never leaves your device.

How can I verify that nothing is uploaded?

Open your browser's DevTools, switch to the Network tab, and process a file. You'll see no requests carrying your data. Our Content-Security-Policy additionally blocks the site from talking to third-party servers.

Is KeepItLocally free?

Yes — every tool is completely free, with no sign-up, no accounts, and no paid tier. If it saves you time, an optional donation keeps it running.

Does it work offline?

Once a tool page has loaded, processing works even if you disconnect from the internet — because nothing is ever sent anywhere.