Compress an image

Reduce the file size of photographs, screenshots, and website assets without sending images to a server. Choose modern WebP for broadly efficient web delivery or JPG for workflows that require traditional compatibility. Smaller, balanced, and higher-quality presets make the tradeoff understandable without exposing complicated encoder settings.

Compression preserves the original pixel dimensions while re-encoding image data. The preview and exact output size appear before download, making it easy to decide whether the result suits your website, email, listing, or document. PNG transparency cannot be preserved in JPG output; use WebP when transparency matters.

Decoding, canvas drawing, and encoding run in a dedicated browser worker. The source image stays on your device and the page remains responsive. Extremely large photographs can require substantial device memory, particularly on mobile browsers. Use the resize tool first when reducing dimensions will provide a larger and more predictable saving than quality compression alone.

Format choice affects both compatibility and size. JPG is dependable for photographs and older publishing systems but has no transparency. WebP often stores a similar-looking photo in fewer bytes and can retain transparent areas, making it useful for modern websites and product assets. Neither option is ideal for every graphic. Logos, diagrams, and screenshots with sharp text may show ringing or soft edges at aggressive settings, so inspect them at normal display size before replacing a source.

The quality control changes how much visual information the encoder discards. A lower setting can produce a much smaller file, but smooth gradients, hair, foliage, and text edges reveal damage first. Start with the balanced preset, compare the output, and move toward smaller only when the intended use tolerates it. Social thumbnails and email previews can often accept more compression than a portfolio image or marketplace product photograph.

File size alone is not the same as page performance. A 4000-pixel photograph displayed at 600 pixels still makes the browser decode unnecessary pixels even after quality compression. Resize oversized assets to their largest real display dimension, then compress the resized copy. For responsive sites, create several widths and let the page select the appropriate one. Always keep an original master because repeated lossy saves compound artifacts.

Transparent PNG inputs require attention. JPG replaces transparency because that format cannot represent an alpha channel. WebP is the safer output when transparent pixels must remain transparent, but verify the preview against both light and dark backgrounds. Fine semi-transparent shadows and antialiased edges are easy to miss on a single checkerboard.

Processing performance depends on pixel count rather than only the file’s megabytes. A highly compressed phone photo may decode into tens of millions of pixels. If a mobile browser struggles, close other tabs or resize on a desktop. FileGizmo reports the actual output instead of claiming a fixed reduction that cannot be guaranteed across different image content.

Download the compressed copy and test it in the destination that matters. Confirm transparency, orientation, color, and legibility on both a large screen and the smallest expected display. Compare bytes rather than filename extensions alone, and keep the master image outside the delivery folder so a later edit does not begin from an already lossy derivative.