Image Compressor
Compress JPG, PNG, and WebP images locally with adjustable quality and max width. Batch up to 10 files and see exact savings before you download.
How to Compress Images Online
- 1
Upload your images
Drag and drop one or more images into the upload area, or click to browse your files. ImageSize supports JPG, PNG, and WebP formats up to 50MB each. You can compress up to 10 images in a single batch without creating an account.
- 2
Adjust the quality
Use the quality slider to find the right balance between file size and visual fidelity. For web use, 70–80% quality typically reduces file size by 60–80% with no visible difference on most screens. For printing or archival work, stay above 90% to preserve fine detail.
- 3
Set a maximum width (optional)
If your images are larger than they need to be, set a max width such as 1920px for full HD displays. ImageSize resizes proportionally before compression for maximum savings, which is especially helpful for photos straight from a camera or phone.
- 4
Click Compress
Processing happens entirely in your browser using WebAssembly and optimized algorithms. Depending on file size, results appear in one to five seconds. You will see the original size, compressed size, and percentage saved for each image in the batch.
- 5
Download your images
Save individual files or download all compressed images at once. Original files on your device are never modified — only the exported copies reflect your settings. Use the comparison preview to verify quality before sharing.
Frequently Asked Questions
- Is image compression lossless?
- JPEG and WebP compression at less than 100% quality is lossy, meaning some pixel data is discarded. PNG can be lossless when you avoid aggressive resizing. ImageSize shows a before-and-after preview so you can judge whether the trade-off is acceptable for your use case.
- What's the best quality setting for web images?
- For blog posts, product pages, and social media, 75–85% JPEG quality is the sweet spot for most photos. Hero images on large screens may benefit from 85–90%. Start at 80% and lower gradually if you need smaller files for mobile users on slow connections.
- Will compression affect my image's resolution?
- Compression alone does not change dimensions unless you enable max-width resizing. If you set a max width, ImageSize scales down proportionally first, then compresses. You always see target dimensions and file sizes before downloading.
- Can I compress PNG files?
- Yes. PNG files compress well when they contain large flat areas or can be converted to WebP for web delivery. Photographs in PNG format are often much larger than necessary — consider WebP or JPG output for smaller sizes.
- Are my images uploaded to your servers?
- No. ImageSize never uploads your files. All compression runs locally in your browser, so your photos stay on your device. You can verify this in your browser's Network tab — no image data leaves your machine.
- What's the maximum file size?
- Each file can be up to 50MB, with a maximum of 10 files per batch. Very large images may take longer to process depending on your device's memory and CPU. Close other heavy tabs if processing feels slow.