webp を Homebrew, chocolatey, apt, MacPorts でインストール

プロジェクトリンク

• ホームページ
• リポジトリ
• 上流ドキュメント
• パッケージマネージャページ

コマンドとエイリアス

• cwebp
• dwebp
• gif2webp
• img2webp
• webpinfo
• webpmux

プロジェクトの歴史

Google announced WebP on September 30, 2010 as part of its Make the Web Faster work. The launch post argued that images were a large share of web page bytes and introduced WebP as a developer preview for reducing photo file sizes while preserving visual quality.

The original WebP design used still-image coding techniques derived from the VP8 codec that Google had open-sourced earlier in 2010, with a lightweight RIFF-based container. Google's launch test re-encoded about one million web images and reported an average file-size reduction of 39 percent under its comparison method.

On November 18, 2011, Google announced lossless compression and alpha-channel support for WebP. That update broadened WebP from a JPEG-oriented lossy photo format into a candidate for PNG-like graphics, transparent web assets, and GIF-style animations.

採用の歴史

WebP adoption was gradual because image formats require browser, tooling, CDN, and authoring support. Google's current WebP documentation describes native support in major browsers including Chrome, Safari, Firefox, Edge, and Opera, plus support in many tools and software libraries.

The format's adoption history is tied to web performance practice: developers and site operators use WebP when reducing image transfer size matters more than preserving older universal compatibility. Its eventual broad browser support made it a common output target in image pipelines, static-site generators, CDNs, and asset optimization tools.

使われ方

The reference libwebp distribution provides encoder and decoder tools. Google's getting-started guide documents `cwebp` for converting PNG or JPEG images into WebP and `dwebp` for decoding WebP to formats such as PNG or PPM, while the library API lets applications and browsers add WebP support directly.

In day-to-day package use, `cwebp` is the workhorse for lossy and lossless conversion, `dwebp` is used for inspection or compatibility conversion, `gif2webp` and `img2webp` handle animation workflows, and `webpmux`/`webpinfo` serve metadata, container, and debugging tasks.

パッケージ好きにとっての重要性

For package people, WebP is both a format and a toolchain package. Installing it gives scripts and build systems the canonical CLI encoder/decoder tools, which is why it appears in web optimization, media-processing, browser-adjacent, and static-site workflows.

WebP also marks a period when browser vendors and web-performance engineers tried to replace legacy web image defaults with formats designed around network cost. Even after newer formats such as AVIF appeared, WebP remained important because it reached wide browser and tooling support earlier.

タイムライン

• 2010-09-30: Google announced WebP as a new image format for the web.
• 2010: The initial design was based on VP8 intra-frame coding and a lightweight RIFF container.
• 2011-11-18: Google announced WebP lossless compression and alpha transparency support.
• 2012: libwebp 0.2-era tooling made lossless and transparency modes available in the reference implementation.
• 2025-08-07: Google's getting-started documentation still described libwebp command-line tools and API usage.

Related projects

• WebP is related to WebM and VP8 through its compression lineage, to libwebp as the reference implementation, and to competing or complementary image formats such as JPEG, PNG, GIF, APNG, AVIF, and JPEG XL.

ソース

• https://chromium.googlesource.com/webm/libwebp
• https://developers.google.com/speed/webp
• https://developers.google.com/speed/webp/docs/using
• https://developers.googleblog.com/en/webp-a-new-image-format-for-the-web/
• https://developers.googleblog.com/lossless-and-transparency-encoding-in-webp/