MultiKit

PNG to WebP Converter: Smaller Pictures for the Web

  • Free
  • No sign-up
  • Runs in your browser
  • Version 1.0.4
  • Last updated 2026-11-02
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Turn PNG pictures into WebP, a format that makes web pages load faster. A WebP can keep transparency like a PNG and is usually much smaller.

    Everything you enter is processed in your browser and is never sent to a server.

    Browsers:Chrome57+Edge79+Firefox52+Safari15+Opera44+Samsung Internet7.0+Browsers

    How to use

    1. Drop your .png files onto the box, or choose them. You can add up to 50 at once.
    2. Choose the quality. 80 is a good start; lower is smaller, and 100 is the highest. You can also shrink the size.
    3. Download each WebP, or press Download all to get a ZIP. The size of each result is shown next to it.

    Examples

    logo.png with a transparent background
    → logo.webp, still transparent
    WebP supports transparency.
    screenshot.png
    → screenshot.webp, smaller
    The size is shown beside each file, so you can see the saving.
    An already small PNG icon
    → A WebP that may not be smaller
    For tiny flat images the saving can be small or none.
    A 4000 × 3000 PNG, size set to width 1600
    → A 1600 × 1200 WebP
    Setting only the width keeps the proportions, so the height follows.
    My Photo.PNG, together with my photo.png
    → My Photo.webp and my photo.webp
    The extension is replaced. Two files with the same name in the ZIP get -2 added to the second.

    How it works

    This page is the image converter with PNG to WebP already chosen. Your browser decodes the PNG and the WebP is written by libwebp, Google’s encoder, compiled to WebAssembly. Nothing leaves your device.

    What changes in the file

    A PNG stores every pixel exactly. The WebP written here is lossy: it keeps what the eye notices and drops fine detail, and the quality number sets how much is dropped. The transparent part of the picture is stored separately from the colours, and it is kept at full quality, so a soft shadow or a smooth edge does not turn blocky. Google’s WebP FAQ says lossy WebP typically achieves about 30% more compression than JPEG on average; how much a particular picture saves varies.

    Choosing the quality

    Picture A reasonable start
    Photo 75 to 85
    Screenshot with small text 90 or more, and compare
    Logo or icon with flat colours 90 or more, or keep the PNG

    Quality is not a percentage of the original size. It is a setting of the encoder, and the same value gives different savings on different pictures, which is why the page shows the size of each result.

    When to keep the PNG

    Keep the PNG as the master copy when you may edit the picture again, when it is going to print, or when a program or upload form only accepts PNG. A PNG is also the better choice for a very small graphic. Use the WebP for the copy that is shown on a web page, where every kilobyte is downloaded by every visitor.

    Sources

    Frequently asked questions

    Why convert PNG to WebP?
    Smaller files mean faster pages and less data. WebP photos are usually clearly smaller than the same photo as JPG or PNG.
    Does it lose quality?
    At the quality you choose, a little detail is discarded to make the file smaller. At 80 the difference is hard to see on photos. Text and sharp edges show more, so raise the quality for screenshots.
    Do all browsers and programs open WebP?
    Every current browser does. Some older programs, e-mail clients and upload forms do not, and for those a JPG or PNG is safer.
    Is transparency kept?
    Yes. WebP supports transparent and partly transparent pixels, and the transparency itself is stored at full quality, so the edges of a logo stay clean.
    Is the WebP lossless like the PNG?
    No. This page writes lossy WebP, and even quality 100 is lossy. WebP does have a lossless mode, which Google says produces files 26% smaller than PNG, but if you need every pixel to match the original, keep the PNG.
    Why did my WebP come out bigger than the PNG?
    It happens with small graphics that have few colours, such as icons and simple logos, because PNG already stores those very compactly. The size is shown beside each result, so keep the PNG when the WebP is larger.
    How large a picture can I convert?
    A WebP file can be at most 16383 pixels on a side, and the page also refuses sizes whose total is over 50 million pixels, so that phones do not run out of memory. Use the size option to scale a very large picture down.
    Should I replace all the PNGs on my site?
    Replace photos and screenshots shown on pages, and keep the PNG as your source file for editing. Converting again from an already converted copy adds loss each time.
    Are my pictures uploaded?
    No. They are converted in your browser.

    Guides

    Version history
    • 1.0.4 — Adds what changes in the file (lossy WebP, transparency kept at full quality), how to choose the quality, the size limits, when to keep the PNG, and more examples and questions.
    • 1.0.3 — Puts the format and quality options and the size options on one line on a wide screen, instead of two lines with empty space beside them.
    • 1.0.2 — Makes the search title and description state the supported task, key formats and privacy benefit more clearly.
    • 1.0.1 — Reports conversion completion and failure to connected workflows, so batch runs wait for the full result and ignore cancelled or superseded work.
    • 1.0.0 — First release.

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