CompressifyHow to Reduce Image Size Without Losing Quality
You can usually make an image far smaller with almost no visible difference — if you understand the two levers that control file size. Here's how they work and how to use them.
The two levers: dimensions and quality
Every image file's size comes down to two things:
- Dimensions — how many pixels wide and tall the image is. A 4000×3000 photo has 12 million pixels; a 1000×750 version has under a million. Fewer pixels means a much smaller file.
- Quality (compression) — how aggressively the JPEG encoder throws away detail your eye barely notices. Lower quality = smaller file.
The trick to shrinking an image "without losing quality" is to resize down to the size you actually need first, then apply only gentle compression. Most quality complaints come from over-compressing a full-resolution image instead of resizing it.
Step by step
- Open the Compressify image compressor and choose your photo.
- Turn on "Limit largest side" and set it to what you actually need (e.g. 1000–1600 px for general use, 600–800 px for form photos).
- Adjust the quality slider. Around 70–80 is usually indistinguishable from the original for photos.
- Watch the live preview and file size, then download.
JPEG vs PNG — which to use
| Use case | Best format | Why |
|---|---|---|
| Photographs | JPEG | Compresses photos far smaller than PNG with no visible loss |
| Screenshots, logos, line art | PNG | Keeps sharp edges and text crisp |
| Form / ID photos | JPEG | Portals almost always require JPEG and small sizes |
Compressify exports optimised JPEG, which is what you want for photos and form uploads. A large PNG photo often shrinks by 90% simply by converting it to JPEG.
Settings that quietly bloat your files
- Leaving photos at full camera resolution when they only display small.
- Saving photos as PNG — PNG is great for graphics but huge for photos.
- Quality set to 100 — the jump from 80 to 100 adds a lot of size for detail you can't see.
Hit a specific size
Need to land under an exact KB limit? Use a pre-set shortcut:
Is my photo uploaded anywhere?
No. Compressify compresses images inside your browser, so your photos never leave your device — useful when the picture is an ID or passport photo.