Compress Image to 90KB
The practical target when a form says under 100 KB: close to the limit, with enough margin that a rounding difference will not get your upload refused.
Drop an image to compress it to 90 KB
JPG, PNG or WebP, up to 25 MB. Compressed in your browser, never uploaded.
Under 100 KB
actually means under
A file of exactly 100 KB fails a rule that says less than 100 KB, and plenty of people find that out the slow way. 90 KB keeps nearly all the quality of a 100 KB file and removes the entire category of problem.
Other sizes and settings
Same compressor, different target. Each one opens with its number already set.
Tools that pair well with this one
All free, all in your browser, no signup.
How to compress an image to 90 KB
Three steps, all of them in this browser tab. Nothing is uploaded to a server, so the 90 KB file you end up with never leaves your device.
Add your image
Drag a JPG, PNG or WebP onto the drop area above, or click to pick one. Files up to 25 MB are fine.
Confirm the 90 KB target
90 KB is already selected, so there is nothing to set. Type a different number if your form asked for one.
Compress and download
Press Compress, check the size it actually reached, and download. You will see the original and the 90 KB version side by side first.
The short answer
Why 90KB is the right answer to a 100KB limit
Because the two most common ways an upload gets rejected at 100 KB both disappear once you leave yourself a margin.
The first is the wording. A form that says "less than 100 KB" is stating a strict inequality, and a file at exactly 100 KB does not satisfy it. Systems implement that literally far more often than the people filling in the form expect.
The second is the unit. 100 KB means 102,400 bytes if the system counts in kibibytes and 100,000 bytes if it counts in kilobytes. That is a 2.4% disagreement, which is more than enough to reject a file sitting right on the line, and there is no way to tell from the form which definition is in play.
Compressing to 90 KB puts you roughly 10% clear of both problems. The quality difference between 90 KB and 100 KB on a photograph is essentially invisible, so the margin costs you nothing you can see.
Getting it right
How much quality does the 10KB margin actually cost?
Almost none, and it is worth understanding why, because it explains when the margin is free and when it is not.
Image quality against file size is a curve with rapidly diminishing returns. The jump from 20 KB to 30 KB is dramatic. The jump from 90 KB to 100 KB is close to imperceptible, because by then the encoder is spending the extra bytes on detail that was already nearly right.
That is why shaving 10% off at this end of the scale is nearly free, while shaving 10% off at 20 KB is clearly visible. If you were working near 20 KB, the margin advice would be bad advice.
The exception is images with fine repeating texture: dense foliage, fabric weave, gravel, hair at high magnification. Those keep improving further up the curve than a portrait does. If your image is one of those and the form genuinely accepts 100 KB, try 95 KB instead and keep a little more of the texture.
Formats
JPG vs PNG vs WebP at 90 KB
The same 90 KB target produces three different outcomes depending on what you upload, because the three formats get there by different means.
| Format | How it reaches 90 KB | How it holds up |
|---|---|---|
| JPG | Encoder quality is lowered until the file fits | Comfortable for a correctly sized photo. |
| PNG | Colour count is reduced and the file rewritten | Fine for screenshots and logos, tight for PNG photos. |
| WebP | Encoder quality is lowered, more efficiently than JPG | Usually the best looking of the three at 90 KB. |
If your image is a photograph and it is already a JPG or WebP, 90 KB is a straightforward ask. If it is a PNG photograph, converting it to JPG first will get you a better looking result at 90 KB than compressing it as a PNG will.
Pick a size
90 KB vs 50 KB vs 60 KB
If the number you were given is not 90 KB, one of these is. Each opens the same tool with its own target already set.
The quality difference between neighbouring sizes is much larger at the small end than at the large end. Going from 15 KB to 30 KB transforms a photograph. Going from 200 KB to 500 KB is barely visible on most images. That is worth knowing if you have any choice about which limit to work to.
What the 90 KB compressor does for you
Everything below happens on your own device, in the time it takes to read this line.
Lands under 90 KB
The tool searches for the highest quality whose output still fits under 90 KB, then tells you the size it reached.
Your format, kept
A PNG comes back a PNG, a JPG comes back a JPG. We never convert your file to get a better number.
Nothing leaves your device
The work runs in your browser. No upload, no queue, no copy of your image on anyone's server.
See the saving before you keep it
Original and result side by side, with both exact sizes and the percentage saved, before you download anything.
Works on a phone
The whole tool runs in a mobile browser, which matters when the photo you need to shrink is already on your phone.
Free, with no account
No signup, no watermark and no daily cap. Compress as many files as you need.
Compressing to 90 KB: common questions
What people ask before and after they hit the 90 KB button.
Use 90 KB. It satisfies both a strict less-than rule and either definition of a kilobyte, and the visible quality difference against 100 KB is close to nothing on a normal photograph.
Use 100 KB only if the form clearly says "up to" or "maximum 100 KB" and your image is texture-heavy enough to benefit from the last few kilobytes.
Most likely one of two things. The rule was a strict less-than, so exactly 100 KB failed it. Or the system counts a kilobyte as 1000 bytes while your file manager counts 1024, making your 100 KB file 102.4 KB by the system's arithmetic.
Recompressing at 90 KB clears both without you having to work out which one applied.
Yes, if the form allows it. There is a real and visible quality difference between 50 KB and 90 KB on detailed images, group photos and anything with fine texture, and using the room you are given costs you nothing.
On a tightly cropped headshot against a plain background the difference is much smaller, and 50 KB is perfectly adequate. It depends on how much detail is actually in your image.
No. The compression runs inside your browser, using the canvas your browser already ships with. Your file is read from your own device, processed in memory, and handed straight back to you.
Nothing is transmitted, which means nothing can be stored, logged or leaked. It also means the tool keeps working if your connection drops halfway through.
Free, with no watermark, no account and no daily limit. Compressing to 90 KB costs you nothing and produces a clean file.
There is nothing to sign up for because there is no server doing the work. The tool is the page you are already on.
JPG (and JPEG, which is the same format), PNG and WebP, at up to 25 MB per file. Your file comes back in the format you gave it.
HEIC from an iPhone, AVIF and GIF are not supported yet. If your photo is a HEIC, exporting it as a JPG first will let you compress it here.
Comfortably under the line
90 KB clears a 100 KB rule with room to spare. Drop an image in and check.