Compress an image to 100 KB — documents, forms and quick sharing

How to use Compress Image to 100 KB

1. Choose the photos or scans to reduce.
2. Target size is preset to 100 KB.
3. Choose Save as. JPEG works for photos and scans; WebP is fine for your own website.
4. Leave Allow resizing if quality alone cannot reach the target on, unless the pixel size must stay fixed.
5. Press Compress to 100 KB.
6. Check the result line for each file, then download the versions ending in -100kb.

What it does and when to use it

A 100 KB limit is common for things that are bigger than a passport photo but still need to stay light. It gives a photo of about a megapixel enough room to look natural, and it can hold a single scanned page.

Where it comes up:

• Signatures on entrance exam forms. The NTA bulletins for NEET (UG) 2026 and JEE (Main) 2026 allow a signature from 10 to 100 KB. Those pages, such as the NEET Photo Resizer, also check the minimum.
• Declarations and document images. IBPS asks for a hand-written declaration of 50–100 KB at 800 × 400 px.
• Website images such as blog thumbnails or team photos, where every page load counts.
• Email and chat, when you want to send a few pictures without a heavy attachment.

How it works

The file is processed in your browser by a worker thread. JPEG files go through MozJPEG, which produces smaller files than the browser’s default encoder at the same quality.

The size search has three stages. First, the full-size image at top quality: kept if it is no more than 102,400 bytes. Second, a quality search between 30% and the top. Third, if 30% is still too large and resizing is allowed, a search for the largest size that fits, followed by one more quality search at that size.

If you chose Same format and the file is already under 100 KB, it is returned unchanged.

Worked examples

100 KB is 819,200 bits. Split it across the pixels to see the budget.

A 1,000 × 750 px photo. 750,000 pixels, about 1.1 bits each. That is a reasonable budget for a photo, so the tool can usually keep the full size and pick a sensible quality.

An A4 page scanned at 150 DPI (1,240 × 1,754 px). About 2.2 million pixels, close to 0.4 bits each. Printed text on white paper may still fit, because blank paper is cheap to store. A grey, shadowy phone photo of the same page is much harder.

The IBPS declaration at 800 × 400 px. 320,000 pixels, about 2.6 bits each. Plenty of room; the challenge is more likely to be the 50 KB minimum, which the IBPS Photo & Signature Resizer can handle by padding.

Limits and tips

• Scan, do not photograph, if you can. A flat scan with white paper gives sharper text at 100 KB than a phone photo with shadows.
• Crop the edges. Desk, fingers and dark borders all take bytes. Trim them with the Image Cropper.
• Text documents in grey. For black text on white, a greyscale copy from Image Grayscale can leave more bytes for detail.
• Minimums still apply. A result of 40 KB is fine for “maximum 100 KB”, but not for “50–100 KB”.
• Other budgets: Compress Image to 50 KB for tighter photo limits, Compress Image to 200 KB for bigger photos.