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Webp - Thumbsplus

Using WebP Files with ThumbsPlus: A Complete Guide

WebP is a modern image format developed by Google that provides superior lossless and lossy compression for images on the web. However, because it is relatively new compared to formats like JPEG or PNG, older software versions often struggle to display it.

Part 1: The State of WebP Support in ThumbsPlus

Native Support (Version 10 and Beyond)

If you are running an older version of ThumbsPlus (v7, v8, or v9), you will likely encounter a "Unknown file format" error when trying to open a WebP image. The format simply did not exist in the mainstream when those versions were architected. thumbsplus webp

Verdict: As of 2025, there is no "perfect" native WebP workflow in ThumbsPlus. You are reliant on OS-level codecs. Using WebP Files with ThumbsPlus: A Complete Guide

User Interface Additions

  • File Format dropdown in Save/Export dialogs includes “WebP (*.webp)”.
  • Preferences > Formats > WebP tab:

    Tool A: XnView MP (The Bridge)

    XnView MP is free software that reads WebP perfectly and writes to standard formats. Use it as your pre-processor. File Format dropdown in Save/Export dialogs includes “WebP

    1. In ThumbsPlus, select all JPEG thumbnails.
    2. Right-click > Batch Convert.
    3. In the "Save as type" dropdown, look for WebP File Format (*.webp).