Bundlephobia
bundlephobia.com
Shows what an npm package costs your bundle before you install it
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caniuse.com
Answers whether a browser feature is safe to ship yet.
Support tables for every HTML, CSS and JavaScript feature across browser versions, with the share of real users covered shown as a percentage you can narrow by country. The known-issues notes underneath each table are the genuinely valuable part: 'supported' frequently means 'supported with a caveat that will cost you an afternoon'. The dataset is community-maintained, so a feature that shipped last week can take a while to appear.
Questions
Works the moment the page loads. No account, no email, no trial. Support data is community-maintained and can trail an actual browser release by weeks.
Yes. Can I Use sends your input to its own servers to process it. That is fine for public material; for anything containing personal data, use one of the on-device tools instead.
Support data is community-maintained and can trail an actual browser release by weeks.
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