Free tool
Compress images
Drop in up to twenty images, pick a quality level and an output format, and see exactly how many bytes you saved before you download. Everything happens on your own device — the files are never uploaded.
Drop images here, or choose files
JPG, PNG and WebP, up to 20 at a time. Files are read straight into your browser’s memory — nothing is uploaded anywhere.
How to get the smallest file that still looks right
Compression is a negotiation between file size and visible quality, and the right settlement depends on what the image is and where it will be seen. Three decisions do most of the work.
1. Resize before you compress
This is the step people skip, and it matters more than the quality slider. A 4000-pixel wide photograph displayed in a 800-pixel wide article is carrying five times more pixel data than the screen can show. Dropping the longest edge to roughly twice the display width — enough for high-density screens — often halves the file before a single compression setting is touched.
2. Pick the format that matches the content
JPEG and WebP are built for photographs: continuous tone, gradual colour transitions, no hard edges. PNG is built for flat colour, sharp edges and transparency: logos, icons, screenshots of interfaces. Using the wrong one is expensive in both directions — a photograph saved as PNG can be five times larger than it needs to be, and a logo saved as JPEG picks up visible fuzz around the letterforms.
3. Set quality by looking, not by rule
Start at 78%, compare against the original at the size it will actually be displayed, and only push lower if you cannot see a difference. Skies, skin tones and subtle gradients break down first; busy textures hide compression well. The percentage that works for a landscape will not work for a portrait.
Why this matters beyond page weight
Image weight is usually the single largest contributor to Largest Contentful Paint, one of Google’s Core Web Vitals. On a mid-range phone over a normal mobile connection, a 2 MB hero image can be the difference between a page that feels instant and one that visibly assembles itself. That is a ranking factor, but more importantly it is the first impression a visitor gets.
Related guides
- How to reduce image size for a website without losing quality
- JPG vs PNG vs WebP, explained
- Why image optimisation is crucial for Core Web Vitals
- Compressing JPEGs for email without losing quality