ConvertPort

Free image optimization

Compress PNG Online

Upload PNG images and apply lossless PNG compression levels while keeping transparency intact.

PNG level 0–9Lossless PNG optimizeKeeps transparency

Select images


JPG, PNG, WebP, HEIC, AVIF, TIFF, GIF, or SVG — always converts to PNG. Up to 10MB per image. Max 5 images.

    PNG compression is lossless — pixel data stays intact while file size drops through better encoding. Ideal for UI assets, logos, and screenshots with transparency.

    How to Compress PNG Online

    1. Upload

      Upload PNG files to compress.

    2. Adjust

      Choose a PNG compression level from 0 (fastest) to 9 (smallest). Optional palette mode can help flat-color graphics.

    3. Download

      Download optimized PNG files.

    When to compress PNG

    • Optimize UI icons and logos for web apps
    • Shrink large PNG screenshots
    • Reduce transparent marketing assets for landing pages

    PNG level guidance

    Level 6 is a balanced default. Use 8–9 when file size matters more than encode speed. For photographic content stored as PNG, consider converting to WebP or JPG on a converter page for much smaller files.

    Your images stay on your device

    Your browser opens, processes, and prepares your images for download.

    How local processing works

    • Image files are read from your device.
    • Conversion happens in your browser.
    • Converted files are available to download from the current tab.
    • No account is required.
    • You choose where to save the results.
    • Your original files stay as they are.

    Saving your files

    Download the converted images before closing the tab. ConvertPort does not keep a copy for you to retrieve later.

    Image privacy FAQ

    Does ConvertPort upload my photos?

    No. Image processing takes place on your device.

    Does converting replace the original?

    No. The download is a separate file.

    Can I share a download link for the result?

    Save the file to your device first, then share the file through the app of your choice.

    Frequently asked questions

    Is Compress PNG Online free on ConvertPort?

    Yes. Compress PNG is free with no watermarks.

    Are my images stored on your servers?

    No. Your browser processes the images on your device and prepares the results for download.

    Can I process multiple images at once?

    Yes. Process up to 5 PNG files per batch.