Free Online Image Compressor
How to Use This Image Compressor
- Add your imagesDrag and drop your images onto the upload area, or click to browse your files. You can add up to 20 images at once - the tool supports JPG, PNG, and WebP formats.
- Adjust the quality sliderUse the quality slider to control the compression level. A setting of 80 (the default) provides an excellent balance between file size and visual quality - most images lose 50–80% of their file size with virtually no visible difference. Lower values produce smaller files but may show compression artifacts.
- Choose an output formatPick an output format if you want to convert images. Select "WebP" for the best compression ratio, "JPEG" for maximum compatibility, or "Same as original" to keep the current format. Note that PNG compression is lossless, so the quality slider has no effect on PNG output.
- Set a maximum dimension (optional)Optionally set a maximum dimension to resize images during compression. Images larger than this width or height will be scaled down proportionally while maintaining their aspect ratio.
- Compress and downloadClick "Compress All" to process your batch. The tool shows real-time progress and file size savings for each image. After compression, click a thumbnail to compare before & after, then download individual images or use "Download All" to save everything at once.
All compression happens entirely in your browser using the Canvas API. Your images are never uploaded to any server - they stay on your device throughout the entire process.
What is Image Compression?
Image compression reduces the file size of an image by removing redundant or less important data. There are two types: lossy compression, which permanently discards some image data to achieve smaller sizes, and lossless compression, which reduces size without any data loss. A free online image compressor makes it easy to shrink photos for the web, email, social media, and storage in seconds.
JPEG — lossy compression for photographs
JPEG uses lossy compression and is ideal for photographs and complex images. At quality level 80, a JPEG image typically retains excellent visual quality while being 60–80% smaller than the uncompressed original. The quality degradation at this level is virtually imperceptible to the human eye in most images.
PNG — lossless compression for graphics
PNG uses lossless compression and is best for graphics, logos, screenshots, and images with text or sharp edges. Because no data is discarded, PNG files are larger than equivalent JPEGs but preserve every pixel exactly. PNG also supports transparency, which JPEG does not.
WebP — the modern web format
WebP is a modern format developed by Google that supports both lossy and lossless compression. WebP images are typically 25–35% smaller than equivalent JPEGs at the same visual quality, making it the most efficient format for web use. Browser support for WebP is now universal across all modern browsers.
Why image compression matters for SEO and Core Web Vitals
Image compression matters for website performance, email attachments, social media uploads, and storage management. A webpage with uncompressed images can take 10–20 seconds to load on mobile networks, while properly compressed images load in 2–3 seconds. Google uses page speed as a ranking factor, making image optimization directly important for SEO and Core Web Vitals.
Image Compressor Features
- Supports JPG, PNG, and WebPThe three most common formats on the web.
- Batch compress up to 20 imagesProcess an entire batch at once with per-image progress and savings.
- Quality slider (1–100)Find the exact sweet spot between size and clarity.
- Format conversionOutput as JPG, PNG, or WebP regardless of the input format.
- Resize while compressingSet a max dimension (e.g. 1920 px) to downscale big photos.
- Before/after previewCompare original vs. compressed side by side.
- Download all as ZIPSave the whole batch with one click.
- Zero uploadUses the browser's Canvas API; images stay on your device.
- No watermark, no signup, no limitFree for personal and commercial use.
When to Compress Images
- Faster websitesEvery blog post, WordPress page, Shopify store, and landing page should serve compressed, modern-format images.
- Email attachmentsMost email providers cap attachments at 20–25 MB. Compressing photos keeps them well below that.
- Social media uploadsInstagram, Facebook, LinkedIn, and X re-compress anyway; starting with a smaller file preserves quality better.
- Marketplace listingseBay, Etsy, Facebook Marketplace, and Airbnb load faster and convert better with optimized photos.
- Online forms & applicationsJob portals, visa applications, and school forms often have strict file-size limits (100 KB, 500 KB, 2 MB).
- Cloud storage savingsGoogle Drive, Dropbox, and iCloud fills up quickly with raw phone photos; compression adds breathing room.
- Messaging appsWhatsApp, Telegram, and Signal downscale aggressively. Controlling the compression yourself keeps better quality.
- SEO & Core Web VitalsSmaller images = better LCP and faster mobile ranking.
Image Compression Tips & Best Practices
- Photos → WebP or JPGGraphics/logos/screenshots → PNG or WebP (lossless).
- Start at quality 75–85Go lower only when a strict file-size target forces it.
- Resize before compressingA 6000×4000 photo on a 1080p blog is wasted bytes. Cap at 1600–2000 px wide for most web uses.
- Use WebP for the webAll modern browsers support it, and it is 25–35% smaller than JPG at identical quality.
- Keep an untouched originalCompression is lossy and irreversible; archive master files separately.
- Test on mobileWhat looks fine on a 4K desktop may show artifacts on a high-DPR phone screen.