Jquery's jquery-1.10.2.min.map is triggering a 404 (Not Found)

javascript

debugging

source-maps

devtools

byAlex Kataev·Sep 19, 2024

Experiencing a 404 error for jquery-1.10.2.min.map implies the source map is missing. Let's cut to the chase:

Working with jQuery regardless of the .map file? Ignore it!
Debugging? Download the jquery-1.10.2.min.map from jQuery's official site, place in your JS dir.
Debugging is for nerds? Prevent the 404 by removing the sourceMappingURL comment from jquery-1.10.2.min.js:

// Last line in your jQuery file:
//# sourceMappingURL=jquery-1.10.2.min.map
// Hard to see code? Should have kept your source map. 😂

Now, let's dig deeper into the reason behind the nasty 404 and ways to deal with it.

101: Getting to know source maps

Source maps are your "debugging-companion" that transforms minified gibberish back into detailed, understandable code in your browser's DevTools. They're like the GPS of your minified code - guiding you to your original code.

When to keep or ditch a source map?

Source maps are your trusted allies:

Debugging minified code in browser? Keep 'em.
Tracking an error back to the parent file? Yes, please!

If a source map is missing, your DevTools will whine with a 404 error, but remember: it's all bark, no bite. Meaning, your site continues to run. Here’s how to hush it:

Dealing with the 404 culprit

Option 1: Get the map file, host it

Download both minified (jquery-1.10.2.min.js) and uncompressed (jquery-1.10.2.js) versions along with the .map file from jQuery's official page. This is debugging democracy!

Option 2: Toggle it off in DevTools

Toggle settings to communicate to your browser that you love it too much to debug:

Open browser's DevTools.
Into the Settings we go.
Uncheck Enable JavaScript source maps.
Uncheck Enable CSS source maps.

Option 3: Upgrade jQuery

Newer versions of jQuery (1.11/2.1+) have ditched the sourceMappingURL by default. Feel free to upgrade if debugging isn’t your cup of tea!

Embracing source maps in your trade

Brace yourself for faster debugging and smarter workflows by integrating source maps.

Source map and you

A quick checklist for every coder:

Ensure your debugger tools, workflows generate and preserve source maps; yes, Grunt or Gulp, looking at you!

Source map in production

Before hitting the launch:

Custom builds? Decide if source maps are on board.
Consider removing source map references to optimize performance. Your users' bandwidth will thank you!

Deployment tips to live by:

Consistency is key: Always upload .map files with minified .js files.
Be cautious: Your source maps can be an open book that reveals your original source code. Use wisely!