[Image Optimization]•6 min read
Shrinking Images the Right Way: Resize First, Then Compress
1. Order determines the outcome
Most people reach for the quality slider first. The effective order is the opposite.
If a 4000 px-wide photo is displayed at 800 px, the other 3200 px carry bytes without contributing anything visible. Cutting the width to one fifth reduces pixel count to one twenty-fifth. No quality setting delivers a saving of that magnitude.
2. Lossy versus lossless
Lossy compression is irreversible. Re-saving a JPEG accumulates loss with each generation. Keep the original and compress a copy.
3. Picking a format
| Format | Best for | Notes |
|---|---|---|
| JPEG | Photographs | Universal support, no transparency |
| PNG | Screenshots, logos, diagrams | Lossless, transparency, oversized for photos |
| WebP | Most web imagery | 25–35% smaller than JPEG, supports transparency and animation |
| AVIF | Photographs | Smaller than WebP, slower to encode |
Saving a screenshot as JPEG is a common mistake: text edges pick up visible artifacts and the file is not much smaller than PNG anyway.
4. How far to lower quality
For JPEG and WebP, the 0.75–0.85 range is the practical balance point.
The right answer varies per image, so compare visually at the actual display size.
5. Compression and privacy
Phone photos carry EXIF metadata: capture time, device model, and — depending on settings — GPS coordinates. Uploading a photo taken at home can disclose your location.
Compressors that redraw the image through a canvas generally drop EXIF. Behaviour differs between tools, so verify the output file's properties when it matters.
6. The web performance angle
The largest image on a page is usually the LCP element, which means image weight is perceived load time.
loading="lazy" to images below the fold.width and height to prevent layout shift (CLS).7. Tool
The EVEDAYS Image Compressor compresses and converts between PNG, JPG, and WebP inside the browser. With no upload step, the file is never exposed in transit — though this does not protect against malware already on your device.