Compress an image to under 100 KB
Application forms, visa portals, job sites and email attachments all draw the line somewhere, and 100 KB is where it usually lands. Set the budget once and the engine searches for the highest quality that still fits — lowering the resolution only if no quality setting can get there.
- Nothing is uploaded
- Budget: 100 KB
- JPEG · WebP · AVIF
- Unlimited & free
Drop your images here
or paste from the clipboard · ⌘V / Ctrl+V works too
JPG · JPEG · PNG · WebP · AVIF · HEIC · GIF · BMP — no file count limit
Compression settings
Applied to every imageAuto measures each image: it encodes a test pass at several quality levels, scores the result against the original, and keeps the smallest file that still clears a ~40 dB fidelity floor.
Advanced options
Auto applies a halo-free unsharp mask only when an image is scaled below 82%.
Generated in your browser by a synth — no audio file is downloaded, and it stays silent when a batch finishes in a couple of seconds.
WASM codecs are fetched from a public CDN on first use and give slightly smaller files. Every fallback still works offline.
Results
Why 100 KB is the limit you keep hitting
It is not an arbitrary number. Scanning software stores every application as a database row, and the image column is sized generously enough for a passport photo and no more. The limits people actually run into look like this:
| Where | Typical limit | Usual format rule |
|---|---|---|
| Visa and government application portals | 50 KB – 300 KB | JPG almost always |
| Job applications and ATS uploads | 100 KB – 500 KB | JPG or PNG |
| University and scholarship forms | 100 KB – 200 KB | JPG |
| Passport and ID photo services | 30 KB – 100 KB | JPG, fixed dimensions |
| Email attachments | ~25 MB total, but 100 KB keeps replies light | Anything |
| Marketplace and classified listings | 200 KB – 1 MB | JPG or WebP |
The frustrating part is that the form rarely tells you how to get there. Guessing at a quality slider and re-uploading five times is the normal workflow. It does not have to be.
How the target-size search works
The compressor does not apply a preset and hope. It runs a search.
It searches quality first
Starting from a high setting, it encodes the image, weighs the result, and halves the distance to the target — up to seven passes. Because the relationship between quality and file size is monotonic but not linear, a binary search converges on the largest file that still lands under your budget in a handful of attempts rather than a dozen.
It only reduces the resolution if it has to
Dimensions are sacred. Most tools jump straight to resizing, which is what makes a 100 KB photo look like it was taken through a window. Here the pixel size is touched only when no quality setting can reach the budget — and then in gentle steps, so you keep as much of the original frame as the limit allows.
It never hands back a file that is over budget
If the last pass overshoots, it keeps searching downwards. The number you see in the results panel is the real byte count of the file you are about to download, not an estimate.
Getting the most out of a tight limit
- Crop before you compress. Removing the empty sky around a subject removes detail the encoder no longer has to spend bits on. This buys more quality per kilobyte than any setting.
- Do not send a photograph as PNG. A photo in PNG is routinely five to ten times larger than the same picture in JPG. If the form accepts JPG, use it.
- Use WebP or AVIF when the form allows it. Where JPG needs 100 KB, WebP often needs around 70 KB for the same look, and AVIF less again — which means more of your original detail survives inside the budget.
- Check whether the form also caps dimensions. Many ask for exactly 300 × 400 or similar. Compress first, then resize, or you may compress twice.
Other budgets in one place
The same control works for any number. Type 50, 100, 200, 500 or 2000 into the target field — it is kilobytes, and it is the only setting you need to change. On the main compressor you can switch between target size, a fixed quality, and full auto.
Frequently asked questions
Can I compress an image to exactly 100 KB?
Yes — pick Target size and enter 100. The engine binary-searches encoder quality until the output fits under 100 KB, and reports the real byte count of the finished file rather than an estimate.
What if my photo cannot fit in 100 KB at full size?
Then the engine reduces the pixel dimensions in steps until it fits. A very detailed 12-megapixel photograph will usually need some downscaling to reach 100 KB; a 1–2 megapixel image typically reaches the budget on quality alone and keeps every pixel.
Does compressing to 100 KB destroy the quality?
It costs quality, and there is no way around that — 100 KB is a hard budget. What this tool does is spend the budget well: it finds the highest quality that fits instead of applying a fixed preset that might have come in at 40 KB and thrown away detail you were entitled to keep.
Can I do this on my phone?
Yes. The page is touch-first and the compressor runs on any modern mobile browser, so you can shrink a photo to 100 KB straight from an iPhone or Android photo library without installing anything.
Is there a limit on how many images I can shrink?
No. There is no file-count limit, no daily cap and no watermark. The only practical ceiling is your device's memory, because every image is processed on your own hardware rather than on a server that would have to meter it.
Are my images uploaded to a server?
No. This is a static site with no upload endpoint. Your images are decoded, resampled and re-encoded inside your own browser, so they cannot leave your device even by accident.