Compress Image to 100 KB

How to compress an image to 100 KB

1. Drop your photo on the box above, or click it to choose a file. Target size is already set to 100 KB.
2. Select Compress image. The tool keeps the highest quality between 92% and 40% whose file still fits.
3. Read the result panel: output size, dimensions and quality.
4. Select Download compressed image. The file is never larger than 100 KB, which is 102,400 bytes.

Why I tested this on my own photos

The photos I checked in my articles are 1,200 pixels on the long side, and yet each weighs between 400 and 700 KB. Getting one under 100 KB means throwing away three quarters of it or more. I wanted to see what that costs before writing a page that promises it.

So I took three photos already published here: the Lake Jasna frame from June 2019 and two from a Friday afternoon at Metelkova in Ljubljana in March 2023, shot on my Sony A7 III. I ran each through this page with the 100 KB preset, in Chromium, and wrote down what came out. No best-of-three; the same file in the same browser gives the same result every time.

Limits like this come from someone else's form: job applications, ID photos, school portals. They rarely say why. I cannot see your form, but I can show you what 100 KB does to real pictures.

Before and after at 100 KB

The figure is the easy case. Its background was already out of focus, and smooth blur costs almost nothing to store, so every pixel stayed at 54%. Side by side I have to look hard to find a difference.

The bicycle is the opposite. Rough plaster, painted tiles and thin spokes are fine detail, which is exactly what a JPEG pays for. Even at 40% the full size did not fit, so the tool went down to 928 × 619 px and found 44%. Lake Jasna sits in between: smooth water, busy pebbles, full size at 43%.

What 100 KB is enough for

For a photo looked at on a screen, about 1,200 pixels wide, 100 KB is enough. It is not enough for a full-resolution camera or phone file. A 24-megapixel public-domain test photo (6000 × 4000 px, 6.58 MB) came out at 1206 × 804 px and 41%; a 12-megapixel copy of it, the size many phones save, at 1205 × 804 px and 43%. At 100 KB both end up near 1,200 pixels wide.

Documents are kinder. A 2200 × 1400 px screenshot of a web page (a 466.7 KB PNG test file) fitted at full size at 43%, its large text still readable. Check small print on a scan with your own eyes.

Resize first, then compress

The tool shrinks a photo by itself when quality alone is not enough, but only as far as it must. If you know the size you need, choose it yourself. I resized the bicycle to 800 px on the long side with the Image Resizer (quality 100%, 666.2 KB) and compressed that to 100 KB. It fitted at 800 × 533 px and 64%, against 928 × 619 px and 44% straight from the original.

Fewer pixels at a higher quality usually look cleaner than more pixels at a lower one. If the form shows your photo as a thumbnail, give it a small photo.

When 100 KB is too small

If the limit is yours to choose, 100 KB is tight for textured photos. At 200 KB the bicycle kept its full 1200 × 800 px at 60%, the clay figure reached 87% and Lake Jasna 79%. Enough to survive somebody zooming in.

At 50 KB the bicycle dropped to 656 × 437 px at 40% and the figure to 800 × 533 px at 52%. The tool never goes below 40%, where a JPEG starts to show square blocks, or below 200 px on the long side. When even that does not fit, it says so instead of handing you a broken file.

Tips for getting under 100 KB

• Start from the original export, not a copy saved out of a messaging app; compressing twice adds blur and saves little.
• Crop away what the form does not need first; every pixel removed leaves more of the 100 KB for what matters.
• A blurred background fits at a much higher quality than a busy, sharp scene. If you may choose, send the calmer photo.
• Check how the form counts. Here 1 KB is 1,024 bytes; for a form that counts 1,000 bytes, enter 97.
• A PNG is saved as JPEG, or as WebP when it has transparent areas, so make sure the form accepts that format.

Privacy

Your image never leaves your device. Compression happens entirely in your browser, so nothing is uploaded or stored, and you do not need an account.

Related tools and guides

• Image Compressor: Reduce JPEG, PNG and WebP file sizes while keeping quality high.
• Compress Image to 1 MB: Fit a full-screen photo under 1 MB for email or an upload form while its quality stays high, compressed in your browser without uploading it.
• Compress Image to 200 KB: Bring a photo under 200 KB for a job or visa application while it keeps its full size, compressed in your browser and never uploaded.
• Compress Image to 20 KB: Shrink a signature or a small photo under 20 KB for an application form, and see how far its pixel size has to drop, in your browser with no upload.
• Compress Image to 50 KB: Get a photo or scan under 50 KB for an ID card or exam registration, and see the size and quality it keeps, in your browser with no upload.
• Image Resizer: Resize images by pixels, percentage or longest side.
• Image Converter: Convert JPEG, PNG, WebP and HEIC images directly in your browser.
• Convert PNG to JPG: Turn a PNG into a JPG for a form, an email or a site that will not take PNG. Transparent areas become white, all in your browser.
• Convert HEIC to JPG: Turn iPhone HEIC photos into JPG files that every app, form and computer opens, and see what happens to size, rotation and photo details. No upload.
• Metelkova Ljubljana: My Photos and Complete Visitor Guide: The afternoon in Ljubljana where I took the clay figure and the red bicycle from the table.
• Week 13 of 2023: Photo Editing, Metelkova and an Interview: The Lake Jasna photo from the table, before and after my edit.
• I Built the Tools I Kept Looking For as a Photographer: Why these tools run in your browser instead of on a server.