A photo from a modern phone can be 3 to 8 MB. That is far too big for most online forms, email attachments and website pages. Compressing an image reduces its file size, ideally without any difference you can see. This guide explains how to compress an image the smart way, and how our free Image Compressor does it in your browser.
Two ways to make an image smaller
- Reduce dimensions: fewer pixels, for example 4000 × 3000 down to 1600 × 1200.
- Reduce quality: stronger compression of the same pixels.
Reducing dimensions usually saves the most space with the least visible loss. A 12-megapixel photo is far bigger than any screen needs.
Recommended settings
| Use | Width | Quality |
|---|---|---|
| Online form photo | 600–800 px | 70–80% |
| Email or WhatsApp | 1200–1600 px | 75–85% |
| Website image | 1200–2000 px | 70–80%, WebP if possible |
| Printing | Keep original | 90%+ |
Lossy vs lossless
- Lossy (JPG, WebP): removes detail the eye barely notices; files become much smaller.
- Lossless (PNG): keeps every pixel; best for logos, screenshots and text, but larger for photos.
For photos, JPG or WebP almost always gives the best size. Convert formats with the Image Converter.
Hitting a specific limit
Many portals say “maximum 100 KB” or “under 200 KB”:
- Resize to the dimensions they suggest (if any) with the Image Resizer.
- Compress, starting at 80% quality.
- If still too big, lower quality in steps of 5% and check the result.
Our guide on reducing photo size to KB limits gives exact steps for common requirements.
How to judge quality
Zoom to 100% and look at faces, edges and text. If you cannot see blocky patches or blurring, the compression is fine. Very strong compression shows as blotches in skies and around text.
Privacy
Our compressor runs in your browser, so your photos are not uploaded. Note that compression may remove hidden metadata, such as camera details or location, which is often a privacy benefit.
Batch compression
Compress several photos at once and download them, ideal for product photos or event pictures. To combine them into one document, use the JPG to PDF tool.
Frequently asked questions
How can I compress an image without losing quality?
Reduce the dimensions to what you need and use a quality of about 75% to 85%.
Which format gives the smallest file?
WebP, then JPG, for photos. PNG is larger for photos.
Is my image uploaded?
No. Compression happens in your browser.
Why is my PNG still large?
PNG is lossless; convert photos to JPG or WebP for smaller files.