Compress an image to 1 MB
Get a large photo under a 1 MB limit while keeping full resolution — ideal for CMS uploads, print previews and high-quality sharing.
- Runs in your browser
- Files are never uploaded
- Free, no account
1 KB = 1024 bytes, the same arithmetic your operating system uses.
Only kicks in when quality 5 still overshoots.
A megabyte is enough for almost anything
At 1 MB you can usually keep every pixel of a 24-megapixel photograph and still choose a quality setting in the seventies or eighties. That is the target to reach for when the file has to stay large — a CMS upload limit, a print preview, a photo competition entry, a portfolio submission — rather than when you are optimising a web page, where 200 KB is the better goal.
Bytes are not the same question as print quality
A common mix-up: someone is told a print needs to be “at least 1 MB” and assumes bigger file = better print. What a printer actually needs is pixels. The rule of thumb is 240–300 pixels per printed inch, so:
| Print size | Pixels needed at 300 DPI | Megapixels |
|---|---|---|
| 6 × 4 in | 1800 × 1200 | 2.2 MP |
| A5 | 1748 × 2480 | 4.3 MP |
| A4 | 2480 × 3508 | 8.7 MP |
| A3 | 3508 × 4961 | 17.4 MP |
| Poster, viewed at a distance | 150 DPI is fine | Quarter of the above |
Compressing to 1 MB does not change any of those numbers, because it does not change the pixel count unless the quality search fails. Check the dimensions in the result card against the table, and set the DPI tag afterwards with Change Image DPI so your printer lays it out at the intended physical size.
When the search resizes anyway
Very large or very detailed images — 45-megapixel raw exports, panoramas, dense foliage — can overshoot 1 MB even at low quality. In that case the tool switches to its second pass and searches the pixel scale, reporting exactly what percentage it settled on. If the resolution matters more than the byte target, switch the fallback off; you will get the smallest full-resolution file it could produce and a clear note that the target was not met.
Reading the working
Expand “Show the search” and you see every encode the tool performed: quality, scale and resulting size, marked as fitting or overshooting. For a 1 MB target on a typical photo you will usually see the very first attempt at quality 92 already pass — in which case the tool stops immediately and gives you the highest-quality file that fits, rather than needlessly compressing further just because it could.
Format notes at this size
- JPEG is the right default for photographs headed anywhere other than your own website.
- WebP saves roughly a third of the bytes, which at this size means you keep a noticeably higher quality setting. Modern browsers all read it; some desktop print software still does not.
- PNG is worth using when the image is a screenshot, a chart or a scan of line art — those compress losslessly to well under a megabyte and JPEG would put ringing around every edge.
MB, MiB and the safety margin
We treat 1 MB as 1024 KB — 1,048,576 bytes — and aim 2% under it, so the output satisfies both the 1024-based definition your operating system uses and the 1,000,000-byte definition some upload validators use. The exact achieved byte count is always shown, so you never have to guess which side of the line you are on.
Other targets
500 KB · 200 KB · 100 KB · any target you type.
Questions
Can I keep the full resolution at 1 MB?
Usually yes. Even a 24-megapixel photo generally fits inside 1 MB at quality 70–80 without resizing, so the tool leaves the pixel dimensions alone unless the quality search fails.
Is 1 MB good enough for printing?
For a 6 × 4 in print, easily. For A3 or larger, judge by pixels rather than bytes: you want roughly 240–300 pixels per printed inch, so check the dimensions rather than the file size.
How do I know how much quality I lost?
Expand “Show the search” in the result card. It lists every encode, its quality setting and the resulting byte count, so you can see exactly which setting was chosen and how close the neighbouring ones came.
Does a target of 1 MB mean 1,000,000 bytes?
We use 1024-based arithmetic — 1 MB is 1024 KB, or 1,048,576 bytes — and then aim 2% under, so the result satisfies either definition.