Every image you put on the web is a trade-off between quality and weight. A photo straight off a phone camera weighs 3–8 MB; the same photo, compressed properly, lands between 150 KB and 1 MB with no visible difference at normal viewing size. Getting that right is the single fastest way to make a page load faster, and you do not need Photoshop to do it — a browser-based image compressor handles it in seconds, without uploading your file anywhere.
What image compression actually does
Lossy compression (JPEG, WebP) re-encodes the picture and throws away detail your eye is unlikely to notice — subtle gradients in the sky, noise in shadows, micro-texture in hair. The quality slider controls how aggressive that is. Lossless formats like PNG keep every pixel, which is why a PNG photo is often 5–10× larger than the same photo as a JPEG.
Which quality setting should you use?
The honest answer: lower than you think. Here is what a typical 3456×2234 screenshot compresses to at different settings:
| Quality | Output size | Visual result |
|---|---|---|
| 100% | 2.4 MB | Larger than the original — never use 100% |
| 80% | 520 KB | Indistinguishable from original |
| 70% | 380 KB | Indistinguishable at normal zoom |
| 50% | 240 KB | Slight softness in fine detail |
| 15% | 170 KB | Visible artifacts — too far |
For photos headed to a website, start at 70% and use a before/after comparison to check fine detail like text and hair. For screenshots with small text, stay at 80% or switch to WebP, which handles sharp edges better.
JPEG or WebP?
WebP wins on pure efficiency: expect files 20–30% smaller than JPEG at the same visual quality, and it supports transparency. Every modern browser supports it. Choose JPEG only when the file needs to open in older software or be emailed to someone whose tools you do not control.
How to compress an image step by step
Using the Image Compressor: drop your file anywhere on the page, drag the quality slider while watching the split before/after view, and download the result. The whole process runs locally in your browser — the photo never leaves your device, which also means there is no upload wait and no server queue.
Why this matters for SEO
Page speed is a confirmed ranking signal, and Largest Contentful Paint — usually your hero image — is the metric most sites fail. Cutting a 2 MB hero image to 300 KB routinely moves LCP from 4+ seconds to under 2.5 on mobile. If you resize the image to its display dimensions first (see our Image Resizer), the savings stack.
If you're weighing options, JPEG vs PNG vs WebP: Which Image Format Should You Use? covers this in detail.
If you're weighing options, How to Compress Image File Size in Your Browser covers this in detail.
If you're weighing options, Compress Images for Web: A Practical Guide covers this in detail.
If you're weighing options, Compress an Image to 100KB Without Losing Clarity covers this in detail.