How to compress an image to under 100 KB

1. 01Read the upload requirements. Note the file-size ceiling, accepted formats and minimum pixel dimensions before choosing your starting size.
2. 02Keep your original and resize a copy. In Preview on a Mac, use Tools > Adjust Size, keep the proportions and enable resampling when reducing pixels. On Windows, use Paint's Resize control and enter smaller pixel dimensions.
3. 03Choose an accepted format. Export a photo as JPG from your editor, or try WebP where allowed. Keep PNG for text, graphics or transparency when those details matter.
4. 04Upload the prepared copy to Bitinz. Start with Balanced, then compare Best from the same prepared source if you need a smaller result.
5. 05Download the result and check its file size. If it remains above the limit, reduce pixel dimensions within the destination's rules and compress the new copy. Keep text and facial details clear, and preserve the required minimum dimensions.

For the format decision, see JPG, PNG or WebP. If the destination accepts WebP, JPG to WebP gives you another export to compare.

A pixel-count example: 2000 × 1600 pixels contains 3,200,000 pixels; 1000 × 800 contains 800,000. Halving both width and height leaves one quarter as many pixels. File size does not necessarily fall to one quarter: image content, format and quality affect the encoded bytes.

Check the actual pixel width and height in your editor. Changing only a print-resolution label, while keeping the same pixels, does not remove image detail or reliably solve an upload limit.

The first row verifies the existing homepage JPG files. The resized examples were tested on 2026-10-23: each starts from the same original photo, resized proportionally in an editor and exported at JPEG quality 90 before compression. Balanced and Best use the same prepared input. Sizes use 1 KB = 1000 bytes and are rounded. These are examples from our test photos; your images will differ.

For this photo, the 1200 × 800 copy reaches 78.9 KB at both levels, while the 1600 × 1067 copy stays above 100 KB. At 1000 × 667, Balanced is slightly smaller than Best. Compare your own results to choose the dimensions and level that suit the upload.

An iPhone photo may be HEIF with a .HEIC extension. Export a JPG copy before uploading: on a Mac, open it in Photos or Preview, choose File > Export, then JPEG. Bitinz accepts JPG, PNG, WebP and AVIF, so HEIC needs this preparation first.

• The downloaded file is below the destination's limit, with some room to spare.
• Pixel dimensions still meet the upload requirements.
• The file uses an accepted format; changing its name alone does not convert it.
• Text, facial details and important edges remain clear.
• You have kept the original and tested the actual upload.

If the file is still too large, use the compression troubleshooting guide to choose the next useful adjustment.