Reduce Image Size in KB or MB: Compress to Any Target Size

How to use the image file size reducer

Enter the file size limit you need (100 KB, 200 KB, 1 MB) and the tool binary-searches the encoder quality until the result fits, scaling the image down only if quality alone cannot get there. The quality and scale factor actually used are reported with the result.

Load the imageAny format your browser can read.
Enter your limitFor example 100 KB, 200 KB or 1 MB: whatever the form demands.
DownloadThe statistics panel reports the quality and scale actually used.

About this tool

Government forms, job portals and exam applications routinely enforce hard byte limits. Guessing quality settings until you land under the cap is tedious, so this tool does the search for you: it binary-searches the encoder quality across up to eight passes, keeping the best result that fits.

If quality alone cannot reach the target (common when the image has far more pixels than the limit allows), it progressively scales the image down and searches again. If even that fails, it says so plainly instead of handing you an oversized file.

What you get

Binary search over encoder quality to hit the budget
Automatic downscaling when quality alone is not enough
Works with JPG, WebP and PNG (PNG uses palette steps)
Reports the exact quality and scale factor applied
Clear failure message when the target is unreachable

When to use the image file size reducer

Government and exam portals

Application forms routinely demand photographs under 100 KB or documents under 200 KB, and reject anything larger without explanation.

Job applications

Recruitment systems often cap CV photos and portfolio images at a specific size.

Email and messaging limits

Some services refuse an attachment outright unless it is under a specific size. Set that size as the target.

API and CMS upload caps

Many services enforce a hard byte limit per asset regardless of dimensions.

Realistic targets by image type

Image	Achievable target	Likely outcome
Passport photo, 413 × 531 px	20-50 KB	Comfortable at quality 80+
Scanned document, A4	100-200 KB	Readable; use WebP if allowed
Web photo, 1200 px wide	100-200 KB	Good quality retained
Full 12 MP photo	200 KB	Will be scaled down automatically
Full 12 MP photo	1 MB	Keeps full dimensions at ~quality 75
Screenshot with text	100 KB	Use PNG palette reduction instead

How it works

Encoders cannot be asked for a specific byte count. You give them a quality value and find out the size afterwards. So the tool searches: it encodes at the midpoint of the quality range, checks the result against your budget, and narrows the range in the direction that helps. Eight probes converge to within about 1.5 quality points, and the best result that fits under the target is kept.

When even the minimum quality cannot reach the budget, the problem is pixel count rather than encoding precision. The image is then scaled down by a factor derived from how far over the target the smallest encode came out, and the quality search runs again on the smaller canvas. Up to four such steps are attempted, and the total number of encoder calls is capped at 24 so the search can never run away on a slow device.

PNG works differently because it has no quality parameter. There the search steps through palette sizes (256, 128, 64, 32, 16 colours) and only then begins reducing dimensions. If nothing reaches the target, the tool says so plainly and returns the smallest usable result rather than pretending it succeeded.

Common problems and how to fix them

The tool shrank my image's dimensions: The target was unreachable at the original pixel count. Turn off "Scale the image down if needed" to keep the dimensions, and accept that the target may not be met.
The result is under my target but not exactly on it: That is correct behaviour and what forms actually require. Encoders cannot hit an exact byte count, so the search keeps the largest result that stays under the limit. The limit itself is counted at 1000 bytes to the kilobyte, the stricter definition, so the file passes forms that count either way; Windows, which counts in units of 1024, shows it a little lower.
It says the target could not be reached: Your budget is too small for the pixel count. Resize the image first with the Image Resizer, or switch the output format to WebP, which retains far more detail at very small sizes.
The image looks bad at my required size: The limit is too tight for that content. Reducing the dimensions before compressing almost always looks better than compressing a large image very hard.
It took several seconds: For JPG and WebP the search stops after 24 encoder passes. PNG can take up to 36, because it tries each palette size again at every smaller scale. Each pass is fast on a desktop and slower on a phone; the number used is shown in the statistics.

Frequently asked questions

How do I compress an image to exactly 200 KB?

Enter 200 KB as the target. The result will land just under the limit, never exactly on it, since encoders cannot be asked for a precise byte count. Under the cap is what forms actually require.

Why did the tool shrink my image's dimensions?

Because the target was unreachable at the original pixel count. A 12 MP photo cannot become 50 KB while staying 12 MP and remaining recognisable. Turn off automatic downscaling if dimensions must be preserved.

Which format hits small targets best?

WebP, comfortably. At very small budgets it retains noticeably more detail than JPEG. Use JPG only when the receiving system demands it.

What if it cannot reach my target?

You get the smallest usable result plus a clear warning. Reduce the dimensions first with the Image Resizer, then try again.

How many encoding passes does it run?

For JPG and WebP, up to eight quality probes per scale step and at most four downscale steps. PNG steps through palette sizes instead, with up to six downscales. The statistics panel shows how many passes were actually needed.

How do I compress an image to exactly 100 KB?

Enter 100 KB as the target and leave automatic scaling on. The result lands just under the limit, never exactly on it. At 100 KB, images up to about 1000 px wide keep their dimensions comfortably. For a larger photo the tool lowers the quality first, and scales the image down only if even the lowest quality misses the target.

How do I reduce a photo to 20 KB for an application form?

Set the target to 20 KB and leave automatic scaling on. At that budget a full-resolution photo will be scaled down, which is expected and usually what the form wants. Check whether it also specifies pixel dimensions.

Can I set a target for a whole batch?

Yes. Every image in the batch is searched independently against the same target, so each one lands under the limit regardless of its starting size.

What is realistic at each target size?

It depends far more on pixel dimensions than on the number itself. To compress an image to 20kb or 50kb, expect the tool to scale the image down. Those budgets suit passport photos and small avatars, not full photographs. To compress an image to 100kb is comfortable for anything up to about 1000 px wide. To compress a JPEG to 200kb works well at 1200-1600 px, which covers most form uploads. A 1 MB target keeps a full 12 MP photo at its original dimensions. If a form specifies both a byte limit and pixel dimensions, resize first, then set the target.

Reduce an image to a target file size

Before

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Output