Compress an image to 10 MB

Where the 10 MB limit comes from

Ten megabytes is usually an attachment limit rather than an image limit. It is the per-file ceiling on a lot of corporate mail systems, the maximum for many document upload portals, and the upper bound for a UK digital passport photo. Because it is set with documents in mind, it is rarely tuned for photographs — which means the forms behind it often accept a huge image and then fail somewhere later, or accept it and take a very long time doing so.

Files that exceed 10 MB are almost never ordinary phone snapshots. They are high-resolution scans, photographs from a dedicated camera, panoramas, screenshots of very large displays saved as PNG, or images that have been through an editor that saved them uncompressed. If your file is over 10 MB, it is worth knowing which of those it is, because the right fix differs.

What usually goes wrong

At this size the most common error is sending the file without checking, discovering the failure hours later, and then over-correcting so hard that the recipient gets something unusable. This matters more than usual here because 10 MB limits often apply to things that need to stay legible: a scanned contract, an insurance photo, a passport application.

For documents and scans specifically, resolution is the thing to protect. Text stays readable through a surprising amount of compression, but it falls apart quickly once you remove pixels. If you are compressing a scan, set a minimum width in Advanced options so the search cannot trade away the resolution that makes the words legible, and let it use encoder quality instead.

For photographs the opposite is true, and FileBelow will generally find that giving up some resolution costs less than heavy compression does.

Watch for a minimum as well as a maximum

Some official forms specify a size range rather than a ceiling. A UK passport photo, for example, must be no more than 10 MB but also at least 50 KB — a file compressed too far is rejected exactly as firmly as one that is too large. This catches people who, having been told their photo was too big, compress it as hard as their software allows.

When you choose a destination that publishes a minimum, FileBelow shows it as its own line in the compliance checklist, so you can see at a glance that you have landed inside the range rather than below it.

If it still will not fit

Almost nothing fails to reach 10 MB. If it does, the file is either an enormous lossless image or something with dimensions large enough that your browser had to reduce it before it could be worked on at all — FileBelow says so when that happens. In that case, start from a smaller export of the original if you have one, because reducing a reduced image twice loses more than doing it once.