inline-critical-css
Advanced tools
Stream that inlines critical CSS in HTML. Looks at the used CSS on a page and only inlines the CSS that's used.
var inline = require('inline-critical-css')
var pump = require('pump')
var css = `
.red { color: red }
`
var html = `
<html>
<head></head>
<body class="red">Hello world</body>
</html>
`
var stream = inline(css)
pump(stream, process.stdout)
stream.end(html)
hyperstream makes it easy to chain HTML transforms together. I was too lazy to write my own parser + selector so hence it being a stream. Also I use streams for this stuff anyway so it would make a lot of sense to keep it as a stream.
Ideally we'd only inline the "above the fold" CSS, but that requires knowing which tokens are "above the fold". This would require looking at a specific viewport, and checking which tokens are used (e.g. headless chrome or similar). We opted for a slightly simpler option, which hopefully works out well enough for most cases.
Inlining fancy selectors (e.g. .foo:not(:first-child)) is really hard to
determine statically if it's used. The best way to do so would be to launch a
headless chrome instance - but that requires a fair amount of compute
resources. So we don't. If you want that behavior, we recommend writing a
headless chrome module specifically for that (and let us know, we'd be
interested in that!)
transformStream = inline(css)Create a transform stream that inlines critical CSS in HTML.
FAQs
Inline critical CSS in HTML
The npm package inline-critical-css receives a total of 44 weekly downloads. As such, inline-critical-css popularity was classified as not popular.
We found that inline-critical-css demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 8 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
NIST's new password guidelines remove periodic changes and special character requirements, focusing on longer, more secure passwords for better authentication practices.
Security News
A record 2,709 developers participated in the 2024 Ruby on Rails Community Survey, revealing key tools, practices, and trends shaping the Rails ecosystem.
Security News
In 2023, data breaches surged 78% from zero-day and supply chain attacks, but developers are still buried under alerts that are unable to prevent these threats.