When to Keep jQuery
When to Keep jQuery: free step-by-step lesson with examples, common mistakes, and interview tips — part of jQuery Tutorial on Toolliyo Academy.
On this page
jQuery Tutorial · Lesson 86 of 100
When to Keep jQuery
Setup & DOM ✓ → Events Effects AJAX ✓ → Perf & Integrate ✓ → Ship & Projects
Ship & Projects · 4 — Build · ~10 min · Debug and Modernize
What is this?
Keep jQuery when the page is mostly server-rendered, the team is fluent, plugins are paid-for, and migration ROI is poor. Leave it when you are building a dense SPA with complex client state.
Why should you care?
Honest keep/leave decisions save QueryVerse roadmaps from fashion-driven rewrites.
See it live — copy this example
Examples include the jQuery 3.7 CDN. Paste into an HTML file or use Run Example to preview.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>QueryVerse</title>
<style>
body { font-family: system-ui, sans-serif; margin: 1.25rem; }
.box { padding: .75rem; border: 1px solid #ccc; border-radius: 8px; margin: .5rem 0; }
.muted { color: #666; }
button { margin-right: .35rem; margin-top: .35rem; }
input, select, textarea { margin: .25rem 0; }
table { border-collapse: collapse; width: 100%; }
th, td { border: 1px solid #ddd; padding: .4rem .55rem; text-align: left; }
.hidden { display: none; }
.row-odd { background: #f7f7f7; }
.active { font-weight: 700; }
.toast { background: #111; color: #fff; padding: .5rem .75rem; border-radius: 6px; }
</style>
</head>
<body>
<button type="button" id="score">Score a page</button>
<pre id="out" class="box muted"></pre>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
$(function () {
$('#score').on('click', function () {
var score = {
serverRendered: true,
heavyClientState: false,
existingPlugins: true,
teamSkill: 'jquery-strong',
recommendation: 'Keep jQuery for now; extract APIs and add tests'
};
$('#out').text(JSON.stringify(score, null, 2));
});
});
</script>
</body>
</html>
Run Example »
Edit the code below and click Run to see the result in Toolliyo’s live editor.
What happened?
- Score complexity, hiring, performance budgets, and security posture.
- Keeping jQuery still means upgrading versions and deleting dead plugins.
Practice next
- Run the score sample.
- Rescore a real page of yours.
- Change heavyClientState to true and rethink.
- Write the decision in an ADR.
- Schedule dependency upgrades quarterly.
Remember
Keep when SSR + simple UI. Leave for SPA-scale state. Upgrade even if you keep it.
Keep decision ADR
A Wipro bank channel QueryVerse is stable Razor + jQuery with two plugins.
Outcome: The team documents “keep + upgrade” instead of an unplanned React rewrite.
Interview prep for this lesson
Practice these questions aloud after reading—each links to a full structured answer.
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