How Baseline helps you ship less JavaScript

Jad Joubran gives a practical method for auditing package.json: which libraries can be dropped today because the browser does the same job natively. The piece explains Baseline's three states — limited availability, newly available, and widely available — and shows how to use them as a measure instead of a feeling. The gap between the claim that something needs a library and the fact that the browser already does it closes faster than most projects track.

By Redakcija WebAiRadarPublished August 20, 20262 min readwritten by a model

Jad Joubran took a typical package.json and walked through it with Baseline in hand. The outcome is between 60 and 90 kilobytes, measured after compression, that can come out of an average mid-sized application without losing functionality. The piece is not a wish list but a check with numbers.

Internationalization, the easiest 14 kilobytes

The gain is largest here and the risk smallest, because nearly everything in this group is already widely available.

timeago.js, 1 kilobyte, replaced by Intl.RelativeTimeFormat
pluralize, 2.3 kilobytes, replaced by Intl.PluralRules
numeral, 3.9 kilobytes, replaced by Intl.NumberFormat
humanize-duration, 6.6 kilobytes, replaced by Intl.DurationFormat, which is only newly available rather than widely
helper functions for lists, replaced by Intl.ListFormat

HTTP clients, 17 kilobytes

axios goes out, and the built-in fetch and AbortController come in, both widely available.

Account for the differences, though. fetch does not reject on HTTP errors, and it has no interceptors, retries, or upload progress. If you need any of that, you write a thin wrapper — still far lighter than the whole library.

Interface elements, 24 kilobytes

This group pays off best, because the dialog element and the Popover API together delete three to four packages at once.

Modal libraries, replaced by the dialog element
tippy.js, 14 kilobytes, replaced by the Popover API with CSS anchoring
focus-trap, 6.6 kilobytes, unnecessary because focus containment is built into dialog
body-scroll-lock, 1.3 kilobytes, replaced by one CSS rule that hides overflow while the modal is open

Lodash, 8 kilobytes and up

lodash.clonedeep, replaced by structuredClone
lodash.groupby, replaced by Object.groupBy
set operations, replaced by built-in methods such as union and intersection

When not to drop: the `Temporal` case

Temporal reached the final stage and is part of the ES2026 standard, so the temptation is to switch immediately. Its polyfill weighs 44 kilobytes after compression, though — more than the libraries it would replace. Wait for stable support in Safari and entry into Baseline. This is a useful reminder that standardized and production-ready are not the same thing.

Three questions before you delete

Is the replacement safe by Baseline for your audience — not in general, but for the actual visitors in your analytics?
What does the replacement really cost, counting polyfills, support checks, and testing time?
Does the built-in feature cover your real use case, or only the one from the documentation example?

Tools for checking

npm ls --omit=dev --depth=0 lists production dependencies
Bundlephobia shows the size of an individual package
source-map-explorer or vite-bundle-visualizer show the real share of the shipped bundle
webstatus.dev and MDN are where you check Baseline status
the web-features package makes programmatic checks possible, which is useful in continuous integration

An iPad, desktop, and an iPhone each displaying a browser showing an image of a 3D hiking boot model.

Web

Safari 27.0 ships an MCP server, so a coding agent can drive the browser itself

WebKit published the feature list on September 17, 2026, and it is the longest the team has written: 83 features, up from 58 at the first beta in June, and 844 quality fixes against the 525 announced at WWDC. The headline for anyone who builds with a coding agent is the Safari MCP server, which hands the agent the DOM, network requests, screenshots and console output from a real Safari window. Customizable Select turns the real select element into something you can fully restyle, and scroll anchoring stops the page from jumping when content loads in above what you are reading.

WebKit BlogSeptember 18verified

Web

Safari Technology Preview 252 adds named-feature() and lets SVG reach a filter in another file

The preview build came out on September 11, 2026 and covers WebKit changes between 319252@main and 320112@main. Eleven features are new, and two of them extend the same job: how a stylesheet, and then a script, finds out what the engine underneath can do. The named-feature() function asks about a behavior that has no syntax of its own, and the registry behind it holds exactly two entries today. SVG also gained external resources, so the url() reference can finally point at a filter, mask or gradient stored in another document.

WebKitSeptember 11verified

Web

Interop 2027 proposals close on September 23, and untested ideas do not qualify

The call for Interop 2027 Focus Area proposals opened on September 3, 2026 and closes on September 23, 2026. Proposals are filed as issues on the web-platform-tests/interop repository, and two conditions decide almost everything: the technology must already have a mature standard, and it must be testable, because the test results are what the dashboard scores. Anything that fails the second condition is steered toward an Interop Investigation instead. Twenty days is the whole window, and the evidence a good proposal needs takes longer than an evening to assemble.

WebKitSeptember 4verified