About Compress image
Large images are the single most common reason a web page is slow, and the most common reason an email bounces for size. Compression trades a small amount of visual detail for a large reduction in bytes — usually a much better deal than people expect.
Drop in up to 30 images at once, pick a quality level, and download the results. The work happens in your browser using the same image encoders it already uses to display photos, so there is no upload, no queue, and no waiting on someone else's server.
On quality settings. The scale is not linear or intuitive. Going from 100 to 90 typically removes half the file size while being essentially indistinguishable, because quality 100 spends enormous effort encoding detail the eye cannot resolve. 80 is the sweet spot for photographs and what most sites should ship. Between 60 and 70 you start to see softness in fine texture and haloing around hard edges. Below 50 the blocking becomes obvious in flat areas like skies.
Picking a format. WebP is roughly 25–35% smaller than JPEG at matched quality and is supported by every current browser — if you are compressing for the web, it is almost always the right answer. JPEG remains the safe choice for anything being emailed, printed or opened in older software. PNG is lossless, ignores the quality slider entirely, and is the wrong tool for photographs: a PNG of a photo is frequently *larger* than the original JPEG. Use PNG only for screenshots, logos and anything needing transparency.
Transparency. Converting a transparent PNG to JPEG flattens the transparent areas onto white, because JPEG has no alpha channel. That is a deliberate choice here rather than the black background you get from a naive conversion, but if transparency matters, choose WebP — it keeps alpha and still compresses well.
Resizing while compressing. The optional maximum dimension caps the longest side. This is often the bigger win: a 4000px photo displayed in a 800px column is carrying 25 times more pixels than it needs. Images are never upscaled — a smaller image is left alone.
Questions
Are my photos uploaded?
No. Compression runs in your browser using its built-in image encoders. Your photos never leave your device, and the page has no network permission to send them.
What quality should I use?
80 for photographs on the web. 90 if the image is the point and size is secondary. Below 60 the loss becomes visible in skies and fine texture.
Why did my PNG get bigger?
PNG is lossless and poorly suited to photographs. If your source is a photo, choose JPEG or WebP. PNG is for screenshots, logos and transparency.
Can it handle HEIC photos from my iPhone?
Not directly — browsers cannot decode HEIC. Run it through our HEIC to JPG converter first, which ships a decoder so the photo still stays on your device.
How many images at once?
Up to 30 per batch, 100 MB total. They are processed one at a time so memory stays under control on phones.