Compress PNG Online Lossless to Efficient — Your Choice
PNG files are huge compared to modern formats. CompressVault converts PNG to WebP or AVIF — shrinking files by up to 80% — while preserving transparency. All private, all local.
Compress PNG nowPNG to WebP
Convert PNG to WebP for files 50–80% smaller. Transparency (alpha channel) is fully preserved. Supported by all major browsers.
PNG to AVIF
AVIF is the most efficient image format available — often 40–50% smaller than WebP at equal quality. Ideal for modern web delivery.
Transparency Preserved
Logos, icons, and images with transparent backgrounds convert cleanly to WebP — keeping the alpha channel intact, pixel-perfect.
How to compress PNG images online
- 1
Drop your PNG files
Drag and drop one or more PNGs, or use the file picker. Files with transparency are handled automatically — no special steps needed.
- 2
Choose output format and quality
Select WebP for broad compatibility or AVIF for maximum compression. Adjust the quality slider to control the size-vs-quality trade-off.
- 3
Download your optimized files
Download individually or grab the ZIP. Your compressed PNGs — or converted WebP/AVIF files — are saved locally to your device.
Zero uploads, zero tracking
CompressVault runs 100% in your browser using the Canvas API. Your images are never sent to any server — not even ours. No account required, no usage limits, no ads.
Why is your PNG ten times bigger than the WebP version of the same image?
PNG is a lossless format, which means it stores every pixel exactly as the encoder saw it. That is the right choice for diagrams, logos, screenshots and anything with sharp edges or text — but it is a terrible choice for photographs. A 12-megapixel photo saved as PNG can easily weigh 15 to 20 MB, while the same image as a high-quality JPEG comes in under 3 MB. The problem isn't that PNG is doing anything wrong; it is that lossless compression simply can't compete with formats that are allowed to discard information your eye won't notice anyway.
The modern fix is to convert PNG to WebP or AVIF whenever the image is destined for the web, email or a phone. WebP supports both lossless and lossy modes and typically produces files 50 to 80 percent smaller than PNG at visually identical quality. AVIF goes further still, often beating WebP by another 40 to 50 percent. Crucially, both formats fully support an alpha channel — which means a logo with a transparent background or a UI screenshot with rounded corners converts cleanly without any visible fringes or matte colour bleeding through.
Transparency is the reason most people stick with PNG even when they don't need lossless quality. The good news is that you no longer have to choose between small files and a transparent background. CompressVault detects the alpha channel automatically and preserves it through the conversion pipeline, so a transparent-background PNG becomes a transparent-background WebP. If you need to publish to a context that still doesn't accept WebP — some legacy email clients, certain print workflows — keeping the original PNG and just shrinking its dimensions is still a useful middle ground.
There are still cases where keeping PNG makes sense. If the image will be edited again later, lossless preservation matters. If you are delivering assets to a client whose toolchain hasn't caught up to WebP, compatibility wins. And for icons or graphics where the file is already tiny, conversion saves trivial bytes and is rarely worth the change. CompressVault handles all of these flows from the same interface — drop your PNGs, choose whether to convert or just compress, set quality, and download individually or as a single ZIP. Everything runs in the browser, so files never leave your device.
Frequently Asked Questions
What is the best way to compress a PNG file?
For the smallest file size, convert PNG to WebP or AVIF using CompressVault. WebP typically produces files 50–80% smaller than PNG while preserving visual quality. If you need to keep the PNG format, the Canvas API re-encodes the image at a lower quality which still reduces size considerably.
Does converting PNG to WebP preserve transparency?
Yes. WebP fully supports alpha channel (transparency), so converting a PNG with a transparent background to WebP will preserve the transparency. AVIF also supports transparency.
Why are PNG files so much larger than JPEG?
PNG uses lossless compression, which preserves every pixel exactly. This is great for graphics with text, logos, and sharp edges — but it creates large files for photographs. JPEG and WebP use lossy compression that discards imperceptible detail to achieve much smaller sizes.
When should I keep PNG instead of converting to WebP?
Keep PNG when you need maximum compatibility with very old software or when the file will be further edited. For web publishing, email, or sharing, WebP or AVIF is almost always the better choice.
Can I compress PNG online without uploading the file?
Yes. CompressVault compresses and converts PNG images entirely in your browser using the Canvas API. Your files are never uploaded to any server — the entire process runs locally on your device.
Can I batch compress multiple PNG files?
Yes. Drop as many PNG files as you need — CompressVault handles them all in one session. Download the results individually or as a single ZIP file.