<p>Say I have several JavaScript includes in a page:</p>

<pre><code>&lt;script type="text/javascript" src="/js/script0.js"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="/js/script1.js"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="/js/script2.js"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="/js/script3.js"&gt;&lt;/script&gt;
&lt;script type="text/javascript" src="/js/script4.js"&gt;&lt;/script&gt;
</code></pre>

<p>Is there a way i can tell if any of those weren't found (404) without having to manually check each one? I guess i'm looking for an online tool or something similar. Any ideas?</p>

[{'answer_id': 57246, 'author': 'Alex Argo', 'author_id': 5885, 'author_profile': 'https://Stackoverflow.com/users/5885', 'pm_score': 4, 'selected': True, 'text': '<p>If you get the <a href="https://addons.mozilla.org/en-US/firefox/addon/1843" rel="noreferrer" title="Firebug">Firebug</a> firefox plugin and enable the consoles it should tell you when there are errors retrieving resources in the console.</p>\n'}, {'answer_id': 57248, 'author': 'John Calsbeek', 'author_id': 5696, 'author_profile': 'https://Stackoverflow.com/users/5696', 'pm_score': 2, 'selected': False, 'text': "<p>I don't use other browsers enough to know where to find a similar feature in them, but Safari has an <em>Activity</em> window that displays all of the included files for a given web page and which ones were unable to be retrieved.</p>\n"}, {'answer_id': 57255, 'author': 'Joel Coehoorn', 'author_id': 3043, 'author_profile': 'https://Stackoverflow.com/users/3043', 'pm_score': 1, 'selected': False, 'text': "<p>Log your 404's.</p>\n"}, {'answer_id': 57297, 'author': 'Community', 'author_id': -1, 'author_profile': 'https://Stackoverflow.com/users/-1', 'pm_score': 2, 'selected': False, 'text': '<p>If you want to monitor on the fly without actually checking if it exists, then I suggest placing dynamic variables inside the files. Then just do something like this:</p>\n\n<pre><code>var script0Exists = true; // inside script0.js\nvar script1Exists = true; // inside script1.js\n</code></pre>\n\n<p>Then in your other files, just use:</p>\n\n<pre><code>if ( script0Exists ) {\n    // not a 404 - it exists\n}\n</code></pre>\n'}, {'answer_id': 57323, 'author': 'Community', 'author_id': -1, 'author_profile': 'https://Stackoverflow.com/users/-1', 'pm_score': 0, 'selected': False, 'text': "<p>If you don't want to check it manually on the client you will need to do this server-side. You need to make sure whichever webserver you are using is configured to log 404s and then check that log to see which HTTP requests have failed.</p>\n"}, {'answer_id': 1531355, 'author': 'Piskvor left the building', 'author_id': 19746, 'author_profile': 'https://Stackoverflow.com/users/19746', 'pm_score': 0, 'selected': False, 'text': '<p>If your webhost always returns the HTTP result "200 OK", whether the file exists or not (the latter should give a "404 Not Found"), the browser has no way of telling if it received a script or not.</p>\n\n<p>You might try retrieving the files via XMLHttpRequest, examine the data, and if they look like JS, either eval() them, or create a script tag pointing to the exact same URL you downloaded (if the script is cacheable, it won\'t be transferred again, as the browser already has it).</p>\n'}]
['https://Stackoverflow.com/questions/57238', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/5261/']