Image tool
Compress an image
Reduce file size by lowering encoder quality, switching to a more efficient format, or reducing dimensions. The estimated output size updates as you change settings, so you can stop as soon as you're under your limit.
Runs in your browser · nothing is uploaded
Ready when you are
Upload your image
Drop an image here
JPG · PNG · WebP · GIF · HEIC (where your browser supports it)
Or start with a destination
Presets appear as soon as you add an image.
The three levers that actually matter
Dimensions: halving width and height removes about 75% of the pixels. This is almost always the biggest win and the one people forget.
Quality: JPEG and WebP are lossy. Quality 0.8–0.85 is usually indistinguishable from the original at normal viewing sizes, while quality 0.6 starts showing artefacts around sharp edges and text.
Format: WebP typically produces smaller files than JPEG at comparable quality, and supports transparency like PNG.
Why results vary between images
Compression works by discarding detail the eye is unlikely to miss. A flat gradient compresses enormously; a photo of foliage or a noisy night shot barely compresses at all. There is no single quality setting that hits a target size for every image, which is why the estimate here is measured from the actual encode rather than guessed.
FAQ
Frequently asked questions
- How do I compress an image?
- Upload it, choose JPG or WebP output, and lower the quality slider until the estimated size is where you want it. Reducing the pixel dimensions at the same time gives the biggest reduction.
- Will compressing reduce quality?
- Lossy formats (JPG, WebP) discard some detail permanently, though at high quality settings this is rarely visible. PNG is lossless — it never changes pixel values, but it also can't shrink photographs much.
- What image format is smallest?
- For photographs, WebP is usually smaller than JPEG at the same perceived quality. For flat graphics and screenshots with few colours, PNG or WebP lossless often wins. File size always depends on the image content and the encoder settings.
- Can I compress an image to under 1 MB?
- Almost always. Scale the longest edge to 1600–2000 px and export as JPG at quality 0.8; most photos land well under 1 MB. If not, drop quality to 0.7 or switch to WebP.
- Are my images uploaded to a server?
- No. Every step — decoding, cropping, resizing and encoding — runs in your browser using the Canvas API. The image file never leaves your device, so nothing is stored or transmitted by us.
Related tools
- Reduce image file sizeReduce image file size to meet an upload limit. Adjust dimensions, quality and format with a live size estimate.
- Convert an image to WebPTurn JPG or PNG files into WebP in your browser to cut page weight. Adjustable quality, no upload required.
- Resize an image to exact dimensionsResize any JPG, PNG or WebP to exact pixel dimensions in your browser. No signup, no upload, no watermark.
- Convert an image to another formatConvert between JPG, PNG and WebP in your browser. Choose quality and background handling, then download.
Related guides
Sources & review
Last reviewed 2026-01-15.
- MDN Web Docs — HTMLCanvasElement.toBlob()