Image Compression
How to Reduce Image File Size
Your image is too large to email, upload, or attach. Here's every way to reduce it — browser, Windows, Mac, iPhone, Android — with no software to install.
Method 1 — Browser compressor (fastest, any device)
Works on any device without installing anything. Drop your image, move the quality slider, see the exact before/after file sizes, and download. Total time: under 15 seconds.
Method 2 — Windows (built-in)
Paint doesn't give you a quality slider — it saves JPEG at a fixed quality. For more control, use the browser compressor above.
Method 3 — Mac (built-in)
Common reasons images are too large
Frequently asked questions
What is the fastest way to reduce image file size?
A browser-based image compressor is the fastest option for one or two images — drop the file, set the quality, download the result. Total time: under 10 seconds. No software installation, no account needed. For batch compression of many images, desktop tools like ImageOptim (Mac) or IrfanView (Windows) are more efficient.
How do I reduce image file size on Windows?
Open the image in Paint, go to File → Save As → JPEG Picture, and choose a location. Paint saves at a fixed quality, but the JPEG format alone is typically much smaller than PNG. For more control, use a browser-based compressor where you can set the exact quality level. The Photos app doesn't offer file size control — Paint or a browser tool is better.
How do I reduce image file size on a Mac?
Open the image in Preview, go to File → Export, and change the Format to JPEG. You'll see a Quality slider — drag it left to reduce file size, right to keep more quality. Around 70–80% quality is a good balance. For PNG files, the Export dialog also includes PNG options, but JPEG will produce a much smaller file for photos.
How do I reduce image file size on iPhone?
iPhones save photos as HEIC by default, which is already compressed. To reduce size further, use a browser-based compressor — open it in Safari, upload the image, compress, and save the result. Alternatively, go to Settings → Camera → Formats and switch to 'Most Compatible' (JPEG), which produces slightly larger individual files but is universally accepted.
Why is my image file so large even though the dimensions look small?
File size depends on both dimensions and format. A 1000×1000 PNG can be 2 MB while a 1000×1000 JPEG of the same photo is 150 KB. PNG stores every pixel without compression loss; JPEG applies lossy compression. If your image is a PNG photo (not a graphic with transparency), converting to JPEG will dramatically reduce the file size.
What image format has the smallest file size?
For photographs, WebP (lossy) is typically the smallest, followed by JPEG. For graphics with transparency, WebP (lossless) beats PNG by 20–35%. For browser compatibility, JPEG is the safest choice — it's accepted everywhere. WebP is supported in all modern browsers but occasionally rejected by older software and upload forms.