Image Compressor

Free Online Image Compressor — Reduce JPEG, PNG & WebP File Sizes Instantly

This image compressor lets you reduce the file size of JPEG, PNG, and WebP images directly in your browser — no account, no upload limits, no waiting for a server. Drop your image, adjust the quality slider, and download a compressed version in seconds. The live before/after comparison slider lets you see exactly what you're trading quality for file size, so you can fine-tune to the right balance for your use case.

Most online image compressors are either too simple (one quality setting, no format control) or too complex (Photoshop-level options you don't need). This one hits the middle: meaningful controls without the overwhelm. Pick lossy or lossless, set the quality level, choose your output format, and download. That's it.

Lossy vs. Lossless Compression — Which Should You Use?

Lossy compression (the default) removes some image data to achieve smaller file sizes. For photos and screenshots, you typically can't see the difference at quality 75–90 while getting 40–70% smaller files. This is what most web-optimized JPEGs use. Set quality to 80 for a good starting point and adjust from there.

Lossless compression keeps every pixel exactly the same and reduces file size by removing metadata and optimizing encoding without any quality loss. The savings are usually smaller (10–30%), but the output is bit-for-bit identical to the original in terms of visual quality. Use lossless for logos, icons, and images where you can't afford any visible degradation. Note: lossless is only meaningful for PNG and WebP — JPEG is always lossy by design, so lossless mode auto-switches to PNG.

Which Output Format Should You Choose?

JPEG is the right choice for photos. It achieves the best compression ratios for photographic content and is universally supported everywhere.

PNG is best for images with transparency, flat colors, text overlays, or logos. It supports lossless compression and an alpha channel, but file sizes are larger than JPEG for photos.

WebP is a modern format supported by all major browsers. It offers better compression than both JPEG and PNG at equivalent quality — often 25–35% smaller than JPEG. Use it when you control the environment (your own website, app, or presentation) and want the best file size–to–quality ratio.

When to Use an Image Compressor

• Website performance: Large images are the single biggest cause of slow page loads. Compress before uploading to your CMS.
• Email attachments: Most email clients reject attachments over 10–25 MB. Compressing photos before sending avoids bounced emails.
• Social media uploads: Platforms recompress your images on upload anyway, often badly. Compress first to retain more control over the output.
• Google Docs / Slides: Large images slow down documents. Compress to keep file sizes manageable without visible quality loss.
• App development: Asset file sizes directly affect app bundle size and load times on mobile.

How the Compressor Works

Compression is handled by the browser-image-compression library, which uses a Web Worker to run the compression off the main thread (so the UI stays responsive during large files). The quality slider maps directly to the encoder's initial quality parameter (1–100 → 0.01–1.0). The before/after slider uses react-compare-slider to render both versions side by side with a draggable divider.