Files never leave your device

CSV ↔ JSON

Convert between CSV and JSON in either direction. Pick your delimiter and header behavior; PapaParse handles quoted fields, embedded commas, and edge cases.

100% Free foreverNo account requiredNo file size limitWorks offlineOpen source friendly

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Select a tool aboveFiles stay on your device

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Base64
Encode and decode Base64Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512 hashesJSON Formatter
Pretty-print, minify, and validate JSONJWT Decoder
Decode JWT header and payload (no signature check)

How it works

Offline File Tools uses WebAssembly and modern browser APIs to process your documents entirely on your device. Unlike other file tools online that upload your sensitive documents to remote servers, your files never leave your computer.

Choose your tool
Select from our free file tools — merge, split, compress, rotate, convert and more.
Upload your file
Drag and drop or click to select. Files are read directly by your browser — nothing is sent anywhere.
Process locally
Your browser uses pdf-lib and PDF.js (WebAssembly) to process the file with full CPU/RAM power.
Download instantly
The result is downloaded directly to your device. No waiting for server uploads or downloads.

Why choose Offline File Tools?

There are many online file editors out there. Here's what makes Offline File Tools different from iLovePDF, Smallpdf, and other competitors.

Zero-upload privacy
Your documents contain sensitive data. Unlike most PDF tools online, we never touch your files — processing is 100% local.
Blazing fast
No upload time, no queue, no server latency. Processing speed is limited only by your own CPU and RAM — usually seconds.
100% free, always
No paywalls, no subscriptions, no "pro plan". Every tool is completely free with no registration required.
Works offline
Once the page loads, you can disconnect from the internet and tools will still work. Great for confidential documents.
No file size limits
Server-based tools cap files at 50–200MB. Since we process locally, you're only limited by your device's available RAM.
Cross-platform
Works on any device with a modern browser — Windows, Mac, Linux, iPhone, Android. No app download needed.
All processing happens entirely in your browser using WebAssembly and JavaScript. Your files are never uploaded to any server and never leave your device. The source code is inspectable — open DevTools and watch: no network requests are made when processing your files.
Yes, all tools are completely free with no registration, no watermarks, and no file size limits. The site is supported by non-intrusive display advertising. We will never introduce paywalls for core functionality.
Since processing happens in your browser, the limit depends on your device's available RAM. Most modern computers with 8GB+ RAM can handle files up to 500MB or larger without issues. There is no artificial server-side cap.
No account, no installation, no plugins. Offline File Tools works directly in any modern web browser including Chrome, Firefox, Safari, and Edge on both desktop and mobile.
The key difference is privacy. iLovePDF and Smallpdf upload your files to their servers for processing — your documents pass through third-party infrastructure. Offline File Tools processes everything locally in your browser, so sensitive legal, financial, or personal documents never leave your device. We're also fully free with no file size paywalls.
Yes! Once the page has fully loaded (including the JavaScript libraries), you can disconnect from the internet and all tools will continue to work. This makes it suitable for processing confidential documents in air-gapped environments.