Use the dimensions your page actually displays, choose JPEG or WebP for quality-controlled photo delivery, keep PNG when lossless transparency is important, and compare the real output size before publishing. Open Compress Image.
Do not send more pixels than the layout needs
Compression cannot fully compensate for unnecessarily large dimensions. A photograph displayed at roughly 1200 pixels wide usually does not need a 6000-pixel source delivered to every visitor. Create a delivery copy at a sensible size while retaining the larger original for future use.
If the dimensions are already correct, skip resizing and focus on the encoding format and quality instead.
Choose a format that matches the visual content
JPEG remains a practical compatibility format for photographs. WebP is widely used for modern web delivery and supports both lossy compression and transparency. PNG is useful for lossless graphics and transparency but can be inefficient for photographs.
The most efficient choice depends on the destination, browser support requirements, transparency, and whether the asset is a photo, screenshot, illustration, or interface graphic.
Test quality at the actual display size
Quality settings are codec controls, not universal percentages of visual quality. A value that looks good on one photo can create visible artifacts on another. Check faces, gradients, text, fine patterns, and sharp edges after compression.
Compare the final bytes as well as the preview. If lowering quality saves very little, keep the cleaner version. If it saves a large amount without visible damage at the intended size, the smaller copy may be a better delivery asset.
Web-optimized files are delivery copies. Keep the best available original so future exports do not start from an already compressed derivative.
Batch similar assets, then review exceptions
A shared output format and quality level can save time when a group of images has similar content and purpose. Use individual overrides for hero images, text-heavy graphics, or transparent assets that need different treatment.
After processing, download and spot-check several results before replacing production assets. File-size targets should support the user experience without turning the optimization process into visible quality loss.
Common questions
Is WebP always better than JPG for websites?
No single format is always best. WebP is useful for modern delivery, while JPEG remains broadly compatible. Compare quality, file size, and destination support.
Should website images be resized before compression?
If the source dimensions are much larger than the displayed size, a proportional resize usually makes sense before or alongside compression.
What quality setting should I use?
There is no universal setting. Preview representative images and compare the actual output bytes at the intended display size.
Can I compress a batch locally?
Yes. The Compress Image tool processes supported images in the browser and supports shared settings plus individual overrides.