Free Online File Compressor

Pure client-side WebAssembly & WebCodecs encoding. Compress images, video, PDF & files 100% locally on your hardware.

100% Local · Files Never Leave Your Device

Compression Mode

or drag & drop here

Paste from clipboard with Cmd+V · Multiple files supported

Supported: JPG · PNG · WebP · AVIF · HEIC

No server upload limit0 KB uploadNo watermark100% Free

Processing happens locally in your browser — nothing is uploaded.

Try a sample:

100% free forever· No paywalls

Files stay on device· 0 KB uploaded

No account needed· Instant drop

How client-side compression works

Three steps from raw payload to optimized file, executed entirely within your browser.

§ 01

Select or Drop Files

Images, videos, or PDFs are read straight into your browser's sandbox memory via the File API. There is zero upload latency.

§ 02

Local Hardware Execution

Client-side WebCodecs and WebAssembly codecs compress files directly on your GPU/CPU cores without remote server delays.

§ 03

Immediate Direct Download

Compressed data is exported into an instant in-memory Blob URL or packed into a ZIP archive. Nothing is ever saved to the cloud.

Engineered for privacy. Built for speed.

The architecture difference between in-browser computing and traditional cloud upload tools.

Client-side

LessMB: Local Processing

Execution happens inside your browser’s WebAssembly memory.

0 KB Upload
Files are read directly from local memory. Works even in Airplane mode without internet.
Device Hardware Acceleration
Uses your GPU/CPU via WebCodecs and WASM. Zero queueing or waiting for servers.
Absolute Privacy
Financial spreadsheets, medical scans, and personal IDs never leave your computer.
100% Free Forever
No premium tiers, no size gates, and no login required.

Server-side

Others: Cloud Upload

Files are transferred over the internet to remote machines.

Gigabyte Uploads
Must upload every single byte before compression can even begin. Slow on mobile data.
Artificial Server Queues
Free users throttled behind paid priority queues.
Privacy Risk
Data sits on third-party disks with uncertain retention and potential AI ingestion.
Paywall Traps
Sudden 25 MB caps demanding credit card subscription sign-ups.

Tools by File Type

Explore All Tools by Category

Choose a local tool for images, videos, PDFs, or archives, with guides for specific formats and platforms.

View Hub

Image Compressor – Compress Images Online

Compress JPG, PNG, WebP, AVIF, and HEIC on your local hardware with instant side-by-side visual comparison.

Specialized Tools & Guides

WebP Compressor

Static WebP

Compress static WebP locally and compare quality and output size.

PNG Compressor

Compress static PNG locally; keep PNG output and check transparency.

HEIC to JPG

Zero Upload

Convert Apple iPhone photos to universal JPG instantly without cloud uploads.

Open Full Image Compression Hub

View Hub

Video Compressor – Reduce Video File Size

Hardware-accelerated WebCodecs compression with precise target MB constraints, no watermarks, and no queue.

Specialized Tools & Guides

HandBrake Web Alternative

No Install

Fast, browser-local video compression without complex software setup.

Compress Video for Discord

Free: 20MB

Choose a target below your Discord account limit and check the result.

Compress Video for Email

Set a target below your mailbox limit and check the finished video.

Open Full Video Compression Hub

View Hub

PDF Compressor – Reduce PDF Size Online

Smart object-stream optimization and image downsampling while preserving crisp selectable vector text.

Specialized Tools & Guides

How to Compress a PDF on Mac

Preview Guide

Follow Preview export steps or choose a local browser compression method.

Compress PDF Without Quality Loss

Keep text selectable and vectors crisp for print and business documents.

Open Full PDF Optimization Hub

View Hub

File Compressor – Archive & Reduce Files

Batch file processing and browser-native ZIP compression with zero remote server transfers.

Specialized Tools & Guides

ZIP File Archiver

Bundle selected files into a local ZIP archive. Already compressed files may not shrink.

Open Full File & Archive Hub

Frequently Asked Questions

Everything you need to know about our local-first browser architecture.

Never. LessMB runs entirely inside your browser via client-side WebAssembly and WebCodecs. Zero bytes of your images, videos, or PDFs leave your computer.