How to compress an image to 100 KB
- Tap Choose image above (JPG, PNG, WebP, HEIC and more) and pick your photo.
- On the Exact KB tab the target is already 100 KB and the rule is At or under target (most portals). Change either if your form says otherwise.
- Tap Compress to target. The gauge shows each pass. A large phone photo usually takes a few seconds on a computer, longer on an older phone.
- Compare the result with the original. The result line shows its pixel size and file size.
- Tap Download result, and upload that file to your form.
Photos at 100 KB
100 KB is roomy for a face: our test portrait kept 1040×1559 pixels, and an indoor selfie 997×1496. Busy scenes keep less, because detail costs bytes:
| Photo | 50 KB | 100 KB | 200 KB |
|---|---|---|---|
| Portrait, plain wall (26 MP) | 676×1013 px | 1040×1559 px | 1581×2372 px |
| Indoor selfie (24 MP) | 606×909 px | 997×1496 px | 1584×2377 px |
| Busy street market (24 MP) | 373×559 px | 515×773 px | 800×1200 px |
| Group photo outdoors (24 MP) | 599×400 px | 868×579 px | 1379×920 px |
| Clear sky, little detail (12 MP) | 1860×2480 px | 2490×3320 px | 3024×4032 px |
Test photos: free-to-use Unsplash photos (12–26 megapixels; Unsplash re-encodes its downloads); PixKB Exact KB, "At or under target", desktop Chromium on our test server, October 2026. Pixel sizes are what the tool chose to fit, and can differ slightly between browsers; bytes are exact. Sizes in decimal KB (1 KB = 1,000 bytes).
Documents at 100 KB: crop first
A lot of 100 KB limits are for documents: certificates, ID cards, letters. We photographed a printed form lying on a table and compressed it two ways:
| Same photo | At 100 KB | Text |
|---|---|---|
| Whole scene (form, table and a mug) | 991×1487 px | The form is a small part of the picture |
| Cropped to the form first | 1146×1055 px | Headings and most text legible; the smallest print soft |
Cropping first put the 100 KB into the document instead of the table. For documents: lay the page flat in even light, photograph it straight on, crop to the paper's edges, then compress. Our guide to scanning a document for upload has measured tips on colour and greyscale.
If the upload accepts PDF, a PDF compressed to 100 KB usually keeps text sharper than a photo, because printed text stays as text.
If the form also sets a pixel size
To reach 100 KB the tool may reduce the pixel size. If your form requires exact dimensions (for example a fixed document size), use its preset, or resize first and tap Keep editing this result before compressing: how to keep an exact pixel size.
Forms and sites around 100 KB
The UPSC 2026 signature upload allows 20–100 KB (three signatures on one sheet; see the details). Visa photos usually allow more: the US visa 240 KB, the India e-Visa 300 KB. For those, use their presets rather than a plain 100 KB target.
Common mistakes
- Photographing a document at an angle or in shadow. Uneven light costs bytes and legibility. Shoot straight on, near a window.
- Not cropping. The table, your hand and the background all use the limit.
- Using a screenshot of a document viewer. It's lower resolution than the photo or the PDF itself.
- Compressing an already-compressed copy. Start from the original.
1,000 or 1,024 bytes?
Forms count a kilobyte either way, and the difference can decide a tight limit: a 101,000-byte file is 101.0 KB to one system and 98.6 KB to another, so it passes one 100 KB limit and fails the next. PixKB aims for the stricter count: a maximum of 100 KB gives at most 100,000 bytes, which passes either way.
Frequently asked questions
How do I reduce a photo to 100 KB?
Choose the photo, keep the target at 100 KB with "At or under", tap Compress to target and download the result.
Will a document be readable at 100 KB?
If you crop it to the page first, mostly yes: in our test, headings and most text stayed legible and only the smallest print went soft. Without cropping, much of the 100 KB goes on the background.
Should I upload a document as a JPG or a PDF?
If the form accepts PDF, a PDF usually keeps text sharper at the same size. Use the PDF compressor for that.
How many pixels does a 100 KB photo have?
It depends on the content: about 1040×1559 for our portrait, 515×773 for a busy street scene. There's no fixed conversion; see pixels to KB.
My form needs 100 KB and an exact pixel size. What do I do?
Resize on the Dimensions tab, tap Keep editing this result, then compress to 100 KB. Or use the form's preset if there is one.
Why is the result a few hundred bytes under 100 KB?
The tool returns the largest file that doesn't go over; JPEG sizes move in small steps.
Is compressing to 100 KB free?
Yes. No signup, no watermark, no daily limit, and the tool runs on your own device.
Is my photo uploaded?
No. It's processed in your browser and saved straight back to your device. You can turn on airplane mode after the page loads and it still works.
Does 100 KB mean 100,000 or 102,400 bytes?
It depends on the form. PixKB keeps the file at or under 100,000 bytes, which passes either way.
Which file types can I start from?
JPG, PNG, WebP, HEIC (iPhone), GIF, BMP, SVG and AVIF. The result is a JPEG, which is what forms with KB limits ask for.
Can I compress several photos at once?
Yes. Drop several images in; each is compressed to the same target and they download together as a ZIP.