JPEG or JPG: is there a difference?
No. JPEG is the name of the standard, from the Joint Photographic Experts Group. The three-letter .jpg extension exists because older Windows systems allowed only three letters. Both extensions hold the same kind of file, and every program reads both. This page names the results .jpeg, which is useful when a system or a script expects exactly that extension.
Why camera JPEGs are so big
A DSLR or phone writes JPEG files at very high quality and full resolution, often 3 to 10 MB. That is more than a screen can show. A 24 megapixel photo has about 6,000 pixels on the long side, while a laptop screen shows about 1,500 to 2,500. Reducing the pixel size with Max width gives a large saving, and a quality of 80 to 85 removes much of the rest.
Colors and profiles
Output files are plain sRGB JPEG, the profile that browsers, portals and printers expect. If your original uses a wide color space such as Display P3 or Adobe RGB, colors are converted and can look slightly less saturated. That is normal when preparing images for the web.
Good settings
- Website or blog: quality 80, Max width 1,920.
- Email: quality 75, Max width 1,600. See compress image for email.
- Upload with a limit: use a size page such as 500 KB.
See also the plain JPG compressor with a quality table. Other formats: JPG, PNG, WebP, HEIC, AVIF.