How to compress a JPG image
JPG uses lossy compression: it discards visual detail your eye is least likely to notice, which is why it is so effective for photographs. Every time you lower the quality, the encoder throws away more high-frequency detail and the file gets smaller. The trick is finding the point where the file is small but the loss is invisible — for most photos that lands somewhere around 70–80% quality.
This JPG compressor runs entirely in your browser. Drop in a JPG file, adjust the quality until the preview looks right, and download the smaller version — no uploads, no sign-up, and no watermark.
How to use it
1. Drop your JPG image onto the drop zone or click to browse.
2. Use the before/after slider to compare the original with the compressed result.
3. Drag the quality slider until the file is as small as you want while still looking good.
4. Download the JPG image. Everything is processed on your device.
Choosing the right quality
Start at 75–80% quality. At that level most photos look identical to the original at a fraction of the size. Drop toward 60% when file size matters more than perfection (email, chat, thumbnails). Below about 50% you will start to see blocky artifacts around edges and in smooth gradients like skies.
JPG is the right choice for photographs and camera images. Switch to PNG only if you need transparency or perfectly sharp text, and consider WebP if you want JPG-like quality at an even smaller size.
Common mistakes to avoid
A few habits quietly ruin image quality or waste file size:
- Compressing from an already-compressed copy instead of the original, which stacks up quality loss. - Pushing lossy quality so low that edges look blocky just to save a few kilobytes. - Using a lossless format for a photograph, or a lossy format for a logo with sharp text. - Forgetting that resizing a large image to the dimensions you actually display it at often saves more than compression alone.
Frequently asked questions
What JPG quality should I use?
For most photos, 75–80% is the sweet spot — visually identical to the original but much smaller. Use 60–70% when size matters more than perfection, and stay above 50% to avoid visible blocky artifacts.
Does compressing a JPG again reduce quality further?
Yes. JPG is lossy, so re-compressing an already-compressed JPG discards a little more detail each time (generation loss). Always compress from the highest-quality original you have rather than repeatedly re-saving.
Why does my JPG look blocky after compression?
That blockiness is JPG artifacting, which appears when the quality is set too low — usually below 50%. Raise the quality slider until the blocks and halos around edges disappear.
Should I compress or resize an image to shrink the file?
They solve the problem differently. Compression lowers the encoding quality so the file is smaller at the same pixel dimensions; resizing reduces the dimensions themselves. If an image is far larger than the space it is shown in, resize it first and then compress — that gives the smallest file with the best on-screen quality.
Is this tool free?
Yes — compressing JPG images here is completely free, with no watermark, no account, and no limit on how many you process.
Will compression change the image dimensions?
No. Compression only changes how the pixels are stored, not the width and height. If you also want smaller dimensions, use the resize tool, which often saves even more space.