Free Online Image Compressor — 100% Local, Privacy First

Image Compressor is a free image compression tool that runs entirely in your browser. No files uploaded to any server, no sign-up required, no watermarks. Supports JPG, PNG, WebP, and AVIF compression and conversion, with automatic target-size compression (200KB/100KB/50KB), batch processing, and ZIP export.

Key Features

• 100% Private — All processing happens locally in your browser
• Target Size — Set exact size (200KB/100KB/50KB), auto-adjusts quality
• Multi-format — JPG / PNG / WebP / AVIF compression & conversion
• Batch & ZIP — Upload multiple files, compress all, export as ZIP
• Bilingual — Chinese and English UI, auto-detected
• No Watermark — Output is completely clean, no branding

Use Cases

• Email Attachments — Compress photos under 200KB for reliable delivery
• Web Optimization — Reduce image sizes to improve Core Web Vitals scores
• Job Applications — Fit headshots and documents into 200KB/100KB limits
• E-commerce — Batch compress product images for Shopify, Amazon, etc.

How It Works in 3 Steps

1. Select or drag in images (JPG/PNG/WebP/AVIF); you can add multiple files at once.
2. Set the goal: compress by ratio, fix the quality, or hit an exact target size (e.g. 200KB / 100KB / 50KB).
3. Compress and download — processing runs 100% locally in your browser; your files never leave your device.

Why Compress Images

Images are the largest source of web page weight: an unprocessed phone photo is often 3-5MB, and Google's Core Web Vitals counts image size directly into LCP (largest contentful paint). Compressing images to a sensible size measurably improves page speed, cuts bandwidth costs, and improves the mobile experience — an investment that pays off for both users and search engines.

In another common scenario, compression is a hard requirement: mail servers, government forms, and application portals routinely cap attachments and photos at 100-200KB. Fitting a headshot or a scanned contract under the limit is only possible with good compression — and high-quality local compression shrinks files without sacrificing visible quality.

Which Format: JPG / PNG / WebP / AVIF

There is no single best format, only the right one for the job: JPG suits photos and rich gradients (great compression, lossy); PNG is lossless and supports transparency — ideal for screenshots, icons, and illustrations, but heavier; WebP is typically 25-35% smaller than JPG at the same quality and supports transparency; AVIF offers the best compression today, though support is still spreading.

This tool does more than compress — it converts between these formats too: turn HEIC phone originals into JPG, or PNG screenshots into WebP, in one step.

FAQ