Private processing
PNG files remain inside the current browser tab and are not sent to an ImageOptimise image-processing server.
Optimise PNG images online without losing pixels
Reduce PNG file size privately in your browser with lossless OxiPNG processing. Preserve decoded pixels and transparency, process up to 25 images and download the completed batch in one ZIP.
25PNG images per batch25MBmaximum per imageLosslessPNG processing
Image optimiser
Drop your images and we’ll optimise them automatically
No upload
Drop images here
or choose files from your device
JPEG, PNG, WebP or SVG · Up to 25 images · 25MB per image
Original0 B
OptimisedPending
Space savedPending
Private Files stay on your device
Automatic No settings to understand
Original size Dimensions are preserved
Built for graphics and transparency
A lossless PNG optimizer for everyday web assets
PNG is useful for logos, screenshots, interface graphics and transparent artwork. ImageOptimise reduces encoding overhead without intentionally changing decoded pixels.
Transparency preserved
Transparent and semi-transparent pixels remain supported throughout the lossless optimisation path.
Original retained when needed
If lossless processing cannot produce a smaller PNG, the original is kept and reported honestly.
Batch ZIP download
Optimise one PNG or a batch of up to 25 and collect the completed results in one ZIP.
How to compress an image
From original image to lighter file in three steps
No account, installation or compression expertise is required.
Add your images
Drag SVG, JPEG, PNG or WebP files into the drop area, or browse your device. You can select one image or a mixed batch of up to 25.
Let the browser optimise them
The tool validates each file and automatically uses the tested codec for its format while keeping the decoded pixel dimensions.
Review and download
See the original size, output size and genuine percentage saved. Download individually or choose Download all as ZIP.
Understand PNG optimisation
Lossless PNG compression protects the decoded image
The optimizer restructures PNG encoding rather than lowering photographic quality or removing transparent content.
Lossless processing
OxiPNG searches for a more efficient lossless representation while preserving the decoded pixel result.
Alpha transparency
Transparent edges, shadows and overlays remain supported, which is important for logos and interface graphics.
Dimensions preserved
Width and height remain unchanged. The separate resize tool is available when smaller pixel dimensions are appropriate.
File size and visual quality
PNG savings depend on how the source was created
Lossless PNG optimisation cannot discard visual detail to manufacture a dramatic saving. Screenshots and graphics exported with inefficient settings may reduce well, while a carefully optimised PNG may remain almost unchanged.
Detailed photographic PNG files can remain large because lossless storage must preserve every decoded pixel. If transparency is not required, converting a photograph to JPEG or WebP may create a much smaller practical output.
Always review important images at normal display size before publishing. Compression results depend on the image content, source encoder and previous processing history.
Current optimiser safeguards
✓Pixel dimensions are preserved by the current compressor.
✓The input image format is preserved.
✓Transparent PNG and WebP content remains supported.
✓SVG artwork remains vector content and is never silently rasterised.
✓A larger processed candidate is discarded in favour of the original.
Common uses
Optimise PNG graphics, screenshots and transparent assets
PNG optimisation is useful for interface images, diagrams, logos, screenshots, overlays and other assets where lossless pixels or transparency matter.
Websites and blogs
Prepare hero images, article photographs and interface graphics before uploading them to a CMS or landing page.
Online stores
Reduce product and category image weight before adding assets to an ecommerce catalogue.
Email and campaigns
Create lighter promotional graphics for campaign production, review and handover workflows.
Reports and presentations
Reduce the source weight of images before placing them into documents, slide decks or downloadable resources.
Portfolio and client delivery
Optimise a batch and provide the completed assets together in one convenient ZIP.
Storage and collaboration
Use smaller working copies where full original encoding weight is not required. Keep original master files separately when needed.
Browser-based privacy
Your current tab owns the temporary image batch
The optimisation code and codecs are delivered to your browser, then supported images are decoded and processed on your device. Image bytes, filenames and job data are not sent to an ImageOptimise image-processing server.
- No account is required to use the compressor.
- Each browser tab maintains its own independent temporary batch.
- Different devices on the same network do not share image sessions.
- Clear All removes the displayed batch; closing the tab ends the session.
Image compression questions
Frequently asked questions
Clear information about formats, privacy, output and batch limits.
Is PNG optimisation lossless?＋
Yes. The PNG path uses lossless OxiPNG processing and does not intentionally alter the decoded pixel result.
Will the PNG optimizer remove transparency?＋
No. Transparent and semi-transparent content remains supported.
Are my PNG files uploaded?＋
No image-processing upload endpoint is used. Supported PNG files are processed inside the current browser tab.
Why is my PNG only slightly smaller?＋
Lossless savings depend on the source encoder and image structure. An already optimised PNG may contain little removable overhead.
Why can a photographic PNG remain large?＋
PNG preserves pixels losslessly. Photographs contain complex colour information and are often more efficiently stored as JPEG or WebP when transparency is not needed.
Will PNG optimisation resize my image?＋
No. Pixel dimensions remain unchanged. Use Resize Images when you intentionally want to reduce width or height.
Can I optimise several PNG images together?＋
Yes. Add up to 25 PNG images, each no larger than 25MB, and download results individually or in one ZIP.
Lossless and private
Optimise PNG images
Optimise your next PNG batch
Add up to 25 PNG images and let lossless browser-based processing begin automatically.