About Compress Image to Size
Compress Image to Size hits an exact file-size budget in kilobytes, not just a quality percentage. Set a target — say 100 KB for an upload limit — and the tool drops JPEG or WebP quality first, then reduces dimensions if it has to, iterating until the file fits. It tells you honestly whether it met the target or hit the smallest achievable size, with a before/after slider to check quality. Nothing is uploaded.
- No uploads
- Browser-only
- Works offline
- 100% free
How it works
- 1
Drop an image
Add one JPEG, PNG or WebP up to 50 MB. Transparency is flattened onto white, since the output formats are re-encoded to hit the byte budget.
- 2
Set the target size
Type a target in KB or pick a preset (50 KB to 1 MB), and choose JPEG (universal) or WebP (smaller for the same quality).
- 3
Compress and verify
The tool iterates quality then dimensions until it fits, then shows whether it met the target and lets you compare before and after.
Compress to Size versus the standard compressor
SnapToolz has two image compressors that solve the problem from opposite ends. The standard image compressor is quality-first: you pick how much quality to keep and see what size you get. Compress to Size is budget-first: you name the exact kilobytes and it searches for the settings that fit. The right one depends on whether you're chasing a look or a limit.
| Your need | Use | Because |
|---|---|---|
| ‘Must be under 200 KB to upload’ | Compress to Size | It works backwards from the byte target |
| ‘Just make it smaller, keep it sharp’ | Compress (standard) | You control quality, not an exact size |
| A hard email or form attachment cap | Compress to Size | Guarantees you land under the line |
| Batch-friendly ‘good enough’ shrink | Compress (standard) | Quality slider is simpler for bulk |
Compress to Size drops quality first to protect resolution, then reduces dimensions only if the target can't be met by quality alone. Output is JPEG or WebP — PNG can't be dialled to an arbitrary byte target.
Hitting a real upload limit without wrecking the image
- Read the limit exactly — ‘2 MB’ usually means 2048 KB, and forms count the encoded file, so target a little under to leave headroom.
- Pick WebP over JPEG when the destination supports it: for the same visual quality it lands smaller, giving the compressor more slack to keep detail.
- If the result says ‘closest achievable size’, the target was too aggressive for this image — raise the budget or accept a dimension reduction.
- Transparency is flattened onto white, so a logo meant to sit on a coloured background should be handled before compressing, not after.
- Need specific pixel dimensions as well as a size cap? Resize first to the required width and height, then compress the smaller image to the byte target.
Frequently asked questions about Compress Image to Size
How is this different from the regular image compressor?
The standard compressor lets you pick a quality level and see the resulting size. This tool works backwards from a size: you name the exact KB budget and it searches for the settings that land under it — ideal when a form demands ‘under 200 KB’ or ‘max 1 MB’ and you can't submit until you're beneath the line.
What if my target size is too small for the image?
It won't pretend. The tool compresses as far as it sensibly can, then reports the closest achievable size and flags that the target was too aggressive for this image. That's more useful than silently producing an unrecognisable, over-crushed picture to force a number.
Does it change the image dimensions?
Only if it has to. It reduces quality first to preserve resolution; when quality alone can't reach the target, it starts scaling the dimensions down as well. The result summary shows the final pixel dimensions, and whether they changed from the original.
Why is PNG not an output option?
PNG is lossless, so it can't be dialled down to an arbitrary byte target the way lossy formats can. Compress to Size re-encodes as JPEG or WebP because those let it trade quality for size smoothly — which is exactly what hitting a precise budget requires.
Privacy, offline use, browser support, and pricing questions are answered on the site-wide FAQ.