Image Compressor

Image Compressor is a free online tool that reduces the file size of JPEG, PNG, and WebP images without significant quality loss. Upload your image, adjust the compression level, and download a smaller file — ready for faster web page loading, smaller email attachments, or more efficient cloud storage. All processing happens in your browser so your images are never sent to any server.

Image file size is one of the biggest factors affecting web page load speed. According to Google, images account for the majority of bytes downloaded on most web pages, and page speed directly affects both user experience and search rankings. Google's Core Web Vitals — particularly Largest Contentful Paint (LCP) — are heavily influenced by image load times. A page that loads in under 2 seconds retains significantly more visitors than one that takes 5 seconds. Compressing images before uploading them to your website is one of the most impactful performance optimisations available.

Image compression comes in two types: lossy and lossless. Lossy compression reduces file size by permanently discarding image data that human eyes are least likely to notice. JPEG uses lossy compression — lower quality means a smaller file but more visible artefacts, higher quality means a larger file but near-original appearance. Lossless compression reduces file size without discarding any data — PNG supports lossless compression, and WebP supports both modes. Our tool lets you control the quality level for JPEG and WebP files, so you can find the ideal balance between file size and visual fidelity for each use case.

The achievable compression ratio depends on the image content and starting quality. A high-resolution smartphone photograph can typically be compressed by 60–80% with no perceptible quality loss at normal viewing sizes. A PNG screenshot with flat colours and text compresses less aggressively — perhaps 10–40%. WebP format generally achieves 25–35% smaller files than JPEG at equivalent visual quality. Starting at 80% quality for JPEG is a widely used recommendation that delivers excellent visual results for web use while dramatically cutting file size.

Web developers and designers compress images before uploading them to websites, e-commerce stores, and content management systems. Photographers compress portfolio images for faster gallery loading. Marketing teams compress campaign images for email newsletters — most email clients have rendering issues with large images, and smaller files reduce bandwidth costs for recipients on mobile data. Social media managers compress images before posting to platforms that apply their own additional compression, which can compound quality loss if the original file is already high quality.

When choosing a format for compression, the file type matters as much as the quality level. Use JPEG for photographs and images with gradients — it achieves the best compression ratios for complex colour information. Use PNG for screenshots, diagrams, logos, and images that require transparency — PNG preserves sharp edges and flat colours without the blockiness JPEG introduces at compression boundaries. Use WebP for web images where you can verify browser support — it achieves smaller files than both JPEG and PNG at equivalent quality, and all modern browsers support it.

Image Compressor works entirely in your browser using the HTML5 Canvas API. Your uploaded image is drawn onto an off-screen canvas and re-exported at your chosen quality level using the browser's built-in image encoder. This approach is private (no server upload), fast, and works offline once the page has loaded. The tool displays the original and compressed file sizes side by side so you can see exactly how much space has been saved before downloading.