Client-Side File Converter & Compressor

Never. FileConvert is 100% client-side. When you drop or select a file, your browser processes the bytes directly in device memory using HTML5 Canvas and pdf-lib. Zero bytes of your sensitive images or documents ever leave your phone or computer. You can verify this by turning off your internet connection-all tools will continue working normally.

FileConvert supports all common formats including PNG, JPG/JPEG, WebP, GIF, SVG, and BMP. You can cross-convert between WebP, PNG, and JPG while choosing your exact target quality or specifying an exact target file size in kilobytes (KB).

We use pdf-lib, an open-source binary PDF manipulation library running in browser JavaScript. It reads the raw byte streams of your PDF files, parses the page dictionary structures, copies page streams into a consolidated document, and serializes the new PDF binary directly to your local downloads without requiring backend server rendering.

Unlike traditional online converters that impose 5MB or 10MB limits, FileConvert has zero arbitrary server limits. The only constraint is your device’s available browser memory (RAM). Most modern smartphones and laptops easily process files up to 200MB+ in seconds.

Heavy operations like image downsampling, quantization, and PDF byte stream packing are scheduled with asynchronous microtasks. This yields control back to the browser main thread between computational steps, ensuring the UI stays fluid at 60fps with minimal input latency during high-resolution processing.