How it works.
Every tool on fwip runs on your device. When you drop a file into a fwip tool, it stays on your machine. It is not uploaded to a server. It is not sent to a cloud. It is not transmitted anywhere. The processing happens in your browser using WebAssembly — compiled code that runs locally, at near-native speed, on your hardware.
What powers fwip
PDF tools
Powered by PDF-lib, pdf.js, and Ghostscript compiled to WebAssembly. Compression, merging, splitting, signing, redaction, OCR, form filling, watermarking — all run in your browser. Ghostscript alone is a 30-year-old PostScript engine trusted by governments and enterprises. We compiled it to WASM so it runs on your machine instead of ours.
Image tools
Canvas API, Sharp (compiled to WASM), and browser-native image processing. Resize, compress, convert, crop, batch process — on-device. Format conversions between JPG, PNG, WebP, BMP, TIFF, GIF, and HEIC happen entirely in your browser's memory.
Video tools
FFmpeg compiled to WebAssembly (ffmpeg.wasm). Convert between MOV, MP4, MKV, AVI, WebM, and more. Compress, trim, rotate, resize, merge, extract audio — your video never leaves your machine. The same FFmpeg engine used by YouTube, VLC, and OBS, running in your browser tab.
Audio tools
FFmpeg (WASM) for format conversion and compression. Web Audio API for analysis and cleanup. Convert between MP3, WAV, FLAC, OGG, AAC, M4A. Trim, merge, clean background noise — all local.
AI tools
On-device AI models loaded via ONNX Runtime or TensorFlow.js (WASM/WebGL backends). Background removal, image upscaling, photo colourisation, OCR (Tesseract.js), and speech-to-text — the models run in your browser, not on a server. The AI has no internet connection to your data. It literally cannot phone home.
Privacy tools
Web Crypto API for AES-256-GCM encryption. PBKDF2 key derivation with 100,000 iterations. File encryption and decryption happen entirely in the browser. Your password never leaves your device. The encrypted output is the only thing that touches your disk.
Data tools
JavaScript-native parsing and conversion. JSON, CSV, XML, YAML, TOML — processed in memory, never transmitted. Format, validate, convert, deduplicate — your data stays in your browser tab and nowhere else.
What never leaves your device
- Your files. No file is ever uploaded, transmitted, or sent to any server. Not temporarily. Not "encrypted in transit." Not at all.
- Your data. No file content is read, logged, stored, or analysed by fwip. We have no server-side processing infrastructure. There is nowhere for your data to go.
- Your identity. No account is required to use the free browser tools. No personal data is collected. No cookies are set. No fingerprinting. No tracking pixels.
What fwip does collect
- Anonymous page view analytics via Plausible (privacy-focused, no cookies, no personal data, GDPR compliant, EU-hosted). fwip knows how many people visited the Compress PDF page. fwip does not know who they are or what they compressed.
- Email address if you join the waitlist or download the desktop trial. Used only for launch notification and trial nurture emails. Not sold. Not shared. Not added to any third-party list.
What happens offline
- Desktop app: Works fully offline after installation. No internet connection required for any tool. The only network request is a single license key check — and that works offline for 30 days via a grace period.
- Browser tools: Require an initial page load to download the tool code and WASM modules. After that, processing is local. If you load a tool page and then disconnect from the internet, the tool still works.
Limitations
We'd rather tell you the edges than pretend they don't exist.
- Large files (500MB+) may be slow or hit browser memory limits. The desktop app handles larger files more reliably because it has direct access to your system's memory.
- AI models (background removal, upscaling, OCR, speech-to-text) require downloading the model on first use — typically 5–50MB. After that, the model is cached in the browser. First run is slower. Subsequent runs are fast.
- Processing speed depends on your hardware. Modern laptops handle most tasks in seconds. Older devices or phones may be slower, especially for video and AI tools.
Why this matters
Most "free" file tools upload your document to their server, process it remotely, and send the result back. Some delete it after an hour. Some keep it for model training. Some don't say.
fwip can't see your files. Not because of a policy. Because of architecture. The file never leaves your machine. There is nothing for us to see.