Image Compressor & Resizer.
Reduce image dimensions and file size directly in your browser. Your selected image stays on your device.
✓ Local browser processingHow image compression works here
The browser decodes your image, redraws it at the dimensions you choose, then exports a new JPEG or WebP file at the selected quality. Lower dimensions and lower quality generally create a smaller file.
When to resize instead of only lowering quality
If a photo is 4000 pixels wide but you only need it for a web form or a small website card, reducing the dimensions usually saves more space than aggressively lowering quality. Keep the aspect-ratio option enabled unless you intentionally want to change the shape.
For a deeper workflow, read How to Compress Images for the Web Without Ruining Quality.
Compression is a quality trade-off
Image compression reduces the data needed to store or transfer a picture. The right setting depends on the use: a website thumbnail may tolerate stronger compression than a photograph intended for printing, while a transparent graphic may need a format that preserves its alpha channel.
Smaller files can improve loading and storage, but aggressive compression can create blockiness, ringing, color shifts or loss of fine detail. Compare the processed image at the size where people will actually see it rather than judging only by file-size reduction.
Keep a high-quality master
For repeated publishing, create a delivery copy from a high-quality original instead of repeatedly recompressing the same file. After export, confirm dimensions, format and visual quality.
Image compression: technical principles
The compressor works by decoding the selected image in the browser, drawing it onto an in-memory canvas, optionally changing its dimensions, and exporting a new image. When the aspect ratio is preserved, a practical scale factor is the smaller of the allowed width ratio and height ratio: scale = min(targetWidth / sourceWidth, targetHeight / sourceHeight, 1). The exported dimensions are then approximately width' = round(width x scale) and height' = round(height x scale). A quality setting is passed to the browser encoder; it is not a promise of a particular percentage reduction because JPEG and WebP encoders spend bits differently depending on image detail, texture, edges and color complexity.
Practical use cases
For a website hero, resize a camera image to the largest display width you actually need before lowering quality. For email or messaging, a moderate dimension limit can reduce attachment size while keeping faces and text recognizable. For a product thumbnail, compare the compressed output at its final display size rather than inspecting it at extreme zoom. Keep a high-quality master copy and generate delivery versions from that source so repeated exports do not compound quality loss.
Privacy and local processing
This page uses browser-side image handling: the selected file is read by the page, processed in browser memory, and turned into a downloadable result locally. The image compressor does not need to upload the selected image, its pixels or the resulting file to an external server for the compression step. That local model is useful for screenshots, personal photos and other files that you do not want transmitted merely to change their dimensions or encoding. Normal browser resources such as the page itself and its static scripts may still be fetched from the website, but the image input is not sent as a conversion payload.
Quality checks before publishing
Choosing settings deliberately
Start with the required display dimensions, then choose a quality level that still preserves the details that matter. Text inside a screenshot, fine hair, foliage and high-contrast edges can reveal compression artifacts sooner than smooth backgrounds. Compare both byte size and visual result across a few settings, and do not assume that a higher quality number produces a proportionally larger file. The practical target is the smallest output that still meets the visual and delivery requirements of its destination.
After compression, verify the output format, pixel dimensions, transparency expectations, visible detail and file size. JPEG is commonly appropriate for photographs but does not preserve transparency; WebP can offer efficient lossy or lossless delivery depending on encoder support. A smaller file is only useful when the resulting image remains fit for its intended purpose.
Image-compression questions
Does a smaller image always look worse?
Not necessarily. A moderate size reduction may be difficult to notice in a photograph, while fine text or line art can show artefacts quickly. Compare the result at the size viewers will use.
Should I resize and compress together?
Use the dimensions the destination actually needs, then adjust quality. Reducing unnecessary pixels can save more than lowering quality alone.