JPEG quality
JPEG quality is the compression level of a JPEG: higher quality keeps more detail in a bigger file, lower quality makes a smaller file with visible artefacts.
JPEG is lossy: it throws away detail the eye is least likely to notice. How much it throws away is set by a quality value — 0 to 100 in most software, or Fine, Normal and Basic in camera menus. Separately, image size (pixel dimensions) controls resolution. Together they decide file size.
Around 85–90 is a common sweet spot for web delivery; above that, files grow quickly for little visible gain.
How it works
The encoder splits the image into small blocks and stores each block's detail with precision set by the quality value. Lower values round more aggressively, causing blockiness and halos around edges. Each time a JPEG is opened and saved again, it loses a little more. Resizing by the long edge — say 2,048 px — reduces pixels, and quality reduces detail per pixel.
An example: a gallery that loads slowly
An event photographer uploads full-size, maximum-quality JPEGs to a live gallery. Guests on venue Wi-Fi wait for each image. Delivering 2,048 px copies at quality 85 instead makes them a fraction of the size, and they still look sharp on any phone.
JPEG quality in CloudTether
CloudTether's Delivery resolution offers Original, Large (4,096 px), Web (2,048 px) and Small (1,024 px), plus Custom, where you choose a long edge from 800 to 8,000 px and a JPEG quality from 60 to 100. Only JPEGs are resized, and resizing happens after the phone's single upload, so it speeds up galleries rather than your upload. At Original, the camera's JPEG is delivered untouched. See resized delivery and JPEG-only and resized delivery.
In the camera
Set the camera's JPEG quality to Fine (or the highest option) for anything you deliver; size it down later if needed, rather than starting with a low-quality original.
Tips and common mistakes
- Avoid re-saving JPEGs repeatedly — edit from RAW or the original.
- Use quality 80–90 for web previews; higher for print.
- Resize for clients on phones; keep originals for the archive.
See also
Put it into practice
CloudTether tethers your camera to your phone and delivers every shot to the cloud, live as you shoot — no laptop.