Image Compressor

Image compression reduces the file size of a JPG, PNG, or WebP photo by removing redundant or less visually important data, so the picture takes up less storage space and transfers faster over a network. For most everyday photos, a large portion of the file size can be removed with no change visible to the human eye, because cameras and phones tend to save far more raw detail than a screen can actually display.

This image size reducer is built for web developers optimizing page load speed, online sellers uploading product photos, and anyone tired of hitting upload limits on email, forms, or content management systems. A quality slider lets you choose exactly how much to compress, so you can trade a small amount of visual quality for a much smaller file when that tradeoff makes sense.

All compression happens directly in your browser using the browser-image-compression JavaScript library, running in a background thread so the page stays responsive even on larger images. Your photo is never uploaded to a server — it is read, compressed, and handed back to you for download entirely on your own device, which keeps personal or proprietary images private.

JPEG uses lossy compression designed for photographs with smooth color gradients, and it typically achieves the smallest file sizes for photos, often 60-90% smaller than an uncompressed original at moderate quality settings. It is not suited to images with sharp text or flat colors, where it can introduce visible blocky artifacts around hard edges.

PNG uses lossless compression and preserves transparency, which makes it the right choice for logos, icons, screenshots, and graphics with flat colors or text — but PNG files are usually much larger than JPEGs for actual photographs, since lossless compression cannot discard visual detail the way JPEG does.

WebP is a newer format that generally produces smaller files than both JPEG and PNG at equivalent visual quality, often 25-35% smaller than a comparable JPEG, and it supports transparency like PNG. Its main limitation is that some older software and a small number of legacy systems still do not support it, so JPEG remains the safer default for maximum compatibility.

Image weight is one of the biggest factors in how fast a webpage loads, and it directly affects Largest Contentful Paint (LCP), a Core Web Vitals metric Google uses in search ranking. As a practical target, a hero image on a webpage should generally stay under 200-300 KB, and thumbnail or product-grid images should stay well under 100 KB, since a typical page loads many images at once.

Beyond compression quality, image dimensions matter just as much: uploading a 4000-pixel-wide photo to display in a 400-pixel-wide box on a page wastes bandwidth regardless of compression level, because the browser still has to download the full file before scaling it down. Resizing an image to the dimensions it will actually be displayed at, before or during compression, is often more impactful than adjusting the quality slider alone.

• Hero/banner images: aim for under 200-300 KB
• Thumbnails and product grid images: aim for under 100 KB
• Resize to actual display dimensions before compressing, not after

The quality slider in this tool controls how aggressively the compression algorithm discards fine image detail, from 10% (maximum compression, most quality loss) to 100% (minimum compression, closest to the original). For most photographs, quality settings between 70% and 85% produce a file that is dramatically smaller than the original while looking nearly identical at normal viewing size, which is why that range is a reasonable starting point for most images.

Pushing the slider below roughly 50% starts to introduce visible artifacts on most photos — blockiness in smooth areas like skies or skin tones, and blurring around fine detail — so that range is best reserved for cases like thumbnails or background images where the image will be displayed very small and full detail is not needed.

This tool keeps the original pixel dimensions of your image by default (it does not resize the photo, only re-encodes it), so a 4000x3000 photo stays 4000x3000 pixels after compression, just at a smaller file size. This is useful when you need the compressed file to still print or display at full resolution later, but it means compression alone won't help if the real problem is that an image's dimensions are far larger than needed for its use case.

Compression is processed one image at a time through the quality slider and download button, which keeps the workflow simple and predictable — you can immediately compare the before-and-after file size for each image before deciding whether to adjust the quality and try again.

Lossy compression, which both JPEG and WebP use, permanently discards some image information every time it is applied, which is why repeatedly compressing an already-compressed JPEG (compress, edit, compress again) gradually degrades quality — a phenomenon known as generation loss. It's best practice to keep an uncompressed or lightly compressed master copy of any important photo and only compress a fresh copy each time you need a smaller file for a specific use.

For images where perfect pixel accuracy matters — screenshots used for technical documentation, medical or scientific images, or graphics with fine text — PNG's lossless compression, even at a larger file size, is usually the safer choice over aggressive lossy compression.