Estimate compression level

A Chrome browser extension that estimates the HTTP compression level of the page.

Estimate compression levelとは何ですか?

Estimate compression levelはLeon Brocardによって開発されたChromeの拡張機能で、その主な機能は「A Chrome browser extension that estimates the HTTP compression level of the page.」です。

拡張機能のスクリーンショット

screenshot

Estimate compression level拡張機能のCRXファイルをダウンロード

Estimate compression level拡張子のファイルをcrx形式でダウンロードし、ブラウザにChrome拡張機能を手動でインストールするか、crxファイルを友達と共有して簡単にChrome拡張機能をインストールします。

拡張機能の使用方法

                        Background

Compression is a core feature of HTTP that improves transfer speed, cache bandwidth utilization and cache utilization.

Lossless data compression algorithms development led to the LZW algorithm (1984), used by the compress application (1985), and then the PKZIP application (1991) with its DEFLATE algorithm which was then used in the gzip format (1992). The zlib library (1995) became a de facto standard compression library for gzip data.

HTTP/1.1 in 1999 (RFC 2616) added support for gzip, compress and deflate compression as content encodings. gzip compression quickly became the default as it compressed better than compress, which used the patented LZW algorithm, and as Microsoft incorrectly implemented deflate as a broken raw deflate stream instead of the correct deflate stream inside a zlib format wrapper.

Compression algorithms generally define a file format and how to decompress it. This allows the user to pick an appropriate compression level: either fast compression, which compresses quickly, but doesn't compress very small or instead best compression, which compresses slowly but generates a smaller output.

With gzip and zlib these levels range from 1 (fast) to 9 (best), with a default of 6.

When you browse to a page with this extension and the content is compressed with gzip, a little badge is shown with the estimated compression level.

If the compression was achieved with a gzip compressor other than zlib, a fractional estimate of zlib compression level is shown.

How does it work?

The chrome extension notes the Content-Length of the page as it is loaded, then fetches the page again, tries to compress it with a variety of levels and then displays the result.

This uses more network and CPU. Use sparingly.

TODO

Some websites use the newer Brotli compression algorithm instead of gzip. This extension does not support Brotli yet.                    

拡張機能の基本情報

名前 Estimate compression level Estimate compression level
ID lgogndmdpoegjafbbedeedmeofohbopo
公式URL https://chromewebstore.google.com/detail/estimate-compression-leve/lgogndmdpoegjafbbedeedmeofohbopo
説明 A Chrome browser extension that estimates the HTTP compression level of the page.
ファイルサイズ 520 KB
インストール数 98
現在のバージョン 0.0.1
最終更新日 2022-03-17
公開日 2022-03-17
評価 1.00/5 合計 1 レビュー
開発者 Leon Brocard
Eメール [email protected]
支払い方法 free
拡張機能のウェブサイト https://github.com/fastly/chrome-extension-estimate-compression-level
ヘルプページのURL https://github.com/fastly/chrome-extension-estimate-compression-level
対応言語 en
manifest.json
{
    "update_url": "https:\/\/clients2.google.com\/service\/update2\/crx",
    "manifest_version": 3,
    "name": "Estimate compression level",
    "version": "0.0.1",
    "action": {
        "default_icon": {
            "128": "images\/128.png"
        }
    },
    "description": "A Chrome browser extension that estimates the HTTP compression level of the page.",
    "icons": {
        "128": "images\/128.png"
    },
    "background": {
        "service_worker": "background.js",
        "type": "module"
    },
    "host_permissions": [
        "http:\/\/*\/*",
        "https:\/\/*\/*"
    ],
    "permissions": [
        "webRequest",
        "webNavigation"
    ]
}