Precision-engineered file size compressor for the modern web.
About File Size Compressor
File Size Compressor is a browser-native file utility that handles the day-to-day file operations most people reach for a desktop app or a cloud service to do. It runs entirely on-device, using the File System Access API and WebAssembly where needed, which means the files you process never leave your machine. Supports drag-and-drop, batch workflows and a clean export pipeline that matches what you would expect from a proper desktop tool — without install, licence or upload.
Problems This Tool Solves
Pasting data into an online tool means trusting a third-party server with your content. - File Size Compressor runs 100% inside your browser — nothing you paste is transmitted, logged, or stored.
Desktop file utilities require installation, licences, and OS-specific builds. - File Size Compressor runs in any modern browser with no install and is identical on Windows, macOS and Linux.
Cloud file-processing services hit quota or demand a subscription for larger files. - File Size Compressor has no quota and no upload — file size is limited only by your device.
Manual batch operations are slow and error-prone. - File Size Compressor processes drag-and-drop batches in parallel with consistent output settings.
How to Use
Drop your files - Drag a single file or a batch — ${n} picks up each one locally.
Configure options - Pick the output format, size, quality or naming rules from a guided form.
Run the operation - Everything processes in-browser — no upload, no queue.
Save results - Download as individual files or a bundled ZIP. Nothing is stored after the tab closes.
Why This Tool Is Better
No uploads, ever - Files never leave your device, which is essential for client work and personal material.
No install - Runs in any modern browser — identical behaviour on Windows, macOS and Linux.
Batch-ready - Process a folder of files with a single drag-and-drop.
Category: File Utilities
This tool runs entirely in your browser. No data is sent to any server. Try the File Size Compressor now - it is free.