Use a JPG quality setting around 80. That number is a common starting point for web photos because the file size drops sharply while the image still looks almost the same as the original. Higher settings give you a bigger file with little visible gain; lower settings quickly introduce blocky artefacts and colour banding. The exact scale varies between programs, so an 80 in one app may not match an 80 in another, but the principle holds: aim for the middle to high end of the scale and let the file size guide you.
How JPG Quality Works
JPG compresses an image by discarding fine detail that human eyes struggle to notice. The quality setting controls how much detail gets thrown away. A higher number means less compression and a larger file. A lower number means more compression and a smaller file, but the trade-off is visible damage. The scale is not universal. One program might call a medium setting; another might call it good. So treat the number as a rough guide and always check the actual result.
When quality goes too low, the image breaks into visible 8x8 pixel blocks, a signature JPG artefact. Gradients, especially in skies, develop harsh bands of colour instead of a smooth transition. These problems are hard to fix after the fact, so it is better to start with a higher setting and reduce the file size by other means first.
Start with Quality 80
For most web images, quality around 80 hits a sweet spot. The file size drops a lot compared to a very high setting, but the visual difference is barely noticeable on a screen. You can test this yourself: save a photo at 80 and at a very high setting, then switch between them in your browser. Unless you zoom way in, you probably will not see a difference. The smaller file loads faster and uses less bandwidth, which matters for page speed and mobile data.
If the image is a simple graphic with flat colours instead of a photo, you might go higher, because artefacts show up more easily in solid areas. If the image is a large background photo where some softness does not matter, you could try a lower setting. But 80 is a safe starting point that works for most cases.
Resize First, Then Compress
Cropping and resizing the pixel dimensions to match the display size saves far more file size than dropping the quality setting. If you upload a very wide photo and show it at a much smaller width, you are wasting space. Scale the image down to the exact width the page uses before you apply JPG compression. That one step can cut the file size by a large amount with zero quality loss.
Order of operations for a web image
- Crop to remove unnecessary edges.
- Resize to the final display dimensions (e.g., a few hundred pixels wide).
- Save as JPG with quality around 80.
This sequence gives you the smallest possible file without introducing visible compression artefacts.
Never Edit and Re-Save a JPG
Each time you open a JPG, edit it, and save it again, the quality drops a little more. The compression algorithm runs again on top of the previous compression, multiplying the damage. After a few cycles, blockiness and banding become obvious even at high quality settings. To avoid this, always keep an original copy of your image. Save your master file in a lossless format like PNG or TIFF, or just keep the original JPG untouched. Make edits on a copy, and when you are done, export a fresh JPG for the web.
Use a Tool That Fits Your Workflow
You do not need expensive software to get a good JPG for the web. A simple online tool can handle resizing and quality adjustment without any sign-up. For example, a free JPG converter like jpg.now lets you convert images between formats, compress JPG files, and adjust settings without installing anything. It also includes a file size calculator and an image info viewer so you can check your results before publishing.
Free utilities like a DPI/PPI converter, aspect ratio calculator, and social media image sizes reference can also help you prepare images for different platforms quickly. The goal is to get a clean, small JPG with as little friction as possible.
Practical Checklist for Web JPGs
- Start with an original that you never overwrite.
- Resize the image to the exact pixel dimensions the page needs.
- Set JPG quality around 80 for photos, higher for flat graphics.
- Check the result for blocky artefacts and colour banding, especially in skies and gradients.
- Use an online tool to compress or convert if your usual software is not giving you the control you need.
This routine keeps file sizes small and images sharp, which helps your site load fast and look good on every device.