Keep original dimensions
Compression changes encoding, not width and height.
Private · Browser-based · No upload
Compress Image Online
Compress image files directly in your browser with JPG/WebP quality controls and lossless PNG optimization.
JPG · PNG · WebP
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Images 0
Right method for each format
JPG and WebP use quality control; PNG uses lossless OxiPNG optimization.
Batch compression
Compress several images, compare before and after sizes, then download individually or all at once.
How to use Compress Image Online
- 1
Add images to compress
Choose, drag or paste one or more JPG, PNG or WebP images.
- 2
Choose the compression method
Set JPG/WebP quality or choose the PNG OxiPNG optimization level. Pixel dimensions stay unchanged by default.
- 3
Compress and download
Compare original and output sizes, then download one result or a ZIP for multiple images.
About Compress Image Online
Compression keeps the original pixel dimensions by default. JPG and WebP use adjustable lossy quality; PNG uses lossless OxiPNG optimization.
Frequently asked questions
Does compression change image dimensions?
Not by default. Compression re-optimizes the image encoding while keeping its original width and height. A 4000 × 3000 image remains 4000 × 3000; if the file is still too large, reduce pixel dimensions as a separate step.
Will compression make my image blurry?
JPG and WebP use lossy compression: stronger compression usually makes a smaller file but can affect fine detail, text edges, and gradients. PNG uses lossless optimization and does not discard pixel data just to reduce size. Start with Balanced and compare the result.
Which compression level should I choose: Fast, Balanced, or Strong?
Fast suits a quick batch, Balanced suits most photos and web images, and Strong prioritizes a smaller file but needs closer quality review. Start with Balanced for faces, product textures, small text, or smooth sky gradients.
Why did my image not become smaller?
Some images are already efficiently encoded, including optimized WebP files, images downloaded from social platforms, and low-detail photos. Recompression may not reduce size and can even make it larger; ViewerPix keeps the original when recompression would increase it.
Should I use JPG, PNG, or WebP?
JPG suits ordinary photos and is widely compatible. PNG suits screenshots, logos, text, and transparent graphics. WebP usually gives a useful balance between quality and size. For photos, choose JPG or WebP; for transparency or crisp text, choose PNG.
Will compression preserve transparent backgrounds?
PNG and WebP can preserve source transparency; compression does not remove a background automatically. For transparent logos, product cutouts, or stickers, use PNG or WebP and check the preview before downloading.
Can I compress several images at once?
Yes. Add several JPG, PNG, or WebP images, compare the before and after size for each, and download items individually or together. Test a representative few images before processing a large set.
Are my images uploaded to a server?
No. Supported image processing runs locally in your browser. Third-party decoder code may be loaded only when a format needs it, but your image itself stays on your device.
Private browser processing
ViewerPix processes supported images on your device. Your image files are not uploaded to a ViewerPix application server for this task.
Compression changes encoding, not pixel dimensions
ViewerPix keeps width and height unchanged by default. JPG and WebP use adjustable lossy quality; PNG uses lossless OxiPNG optimization instead of a fake quality slider.
Why can the output stay the same size?
Some images are already efficiently encoded. If recompressing would make a file larger, ViewerPix keeps the original file instead of replacing it with a worse result.
Image workflow guides
Resize vs compress
Resize changes pixel dimensions. Compress changes encoding and file size. Use resize for layout limits and compression for transfer or storage limits.
Why very large images fail
Decoding and rendering use browser memory. A very large pixel canvas can fail even when the file size looks reasonable.
JPG and transparent pixels
JPG has no alpha channel. Transparent areas need a chosen background color before a JPG export.