jQuery 4 arrived in January 2026. The library is not gone, but it is no longer the automatic answer for every interactive page. The useful question is simpler: what does the project already use, what behavior is required, and what will a new layer cost?
Start with the size of the problem
A small newsletter form often needs only valid HTML, browser validation, and a request to a known endpoint. Native browser APIs can be enough:
<form id="newsletter" method="post">
<label for="email">Email</label>
<input id="email" name="email" type="email" required autocomplete="email" />
<button type="submit" disabled>Subscribe</button>
<p id="status" role="status"></p>
</form>Use jQuery when it already forms a stable part of a maintained product, a plugin ecosystem depends on it, or replacing it would add risk without improving the user experience.
Avoid two competing styles
The worst outcome is often a half-migration where the same screen mixes jQuery state, native listeners, and a component framework. Choose an ownership boundary. New isolated features can use native JavaScript while old modules remain stable until they have a reason to change.
Upgrade deliberately
Before moving a legacy site to jQuery 4, inventory plugins, deprecated APIs, browser support, and automated coverage. Use the migration tooling, fix warnings, and test the actual flows rather than assuming a successful build proves compatibility.
Keep endpoints explicit
A form should stay disabled until it has a validated destination. Do not ship an example endpoint or silently post to the current page. Configuration errors should fail clearly during setup.
Decide by maintenance cost
Choose the smallest technology that the team can understand and operate. Native JavaScript is often enough for new, modest interactions. jQuery remains reasonable when it reduces change risk in a real existing system. Age alone is not an engineering argument.