Why Does Javascript Only Work after Opening Developer Tools in Ie Once?

Why does JavaScript only work after opening developer tools in IE once?

If you’ve ever encountered a situation where your JavaScript code only seems to work in Internet Explorer (IE) after opening the developer tools, you’re not alone. This behavior can be frustrating and puzzling, but fear not, there are a few reasons why this might be happening and some possible solutions to fix it.

1. Compatibility Mode

One possible reason for this behavior is that IE is running in compatibility mode. Compatibility mode is a feature in IE that allows older websites to be displayed properly, but it can also affect the way JavaScript is executed. To fix this, you can add the following meta tag to your HTML:

This meta tag ensures that IE uses the latest rendering engine available, which should prevent compatibility mode from interfering with your JavaScript code.

2. Asynchronous Loading

Another possible reason is that your JavaScript code is being loaded asynchronously. When the developer tools are open, it can cause a delay in the loading of the JavaScript file, giving it enough time to be fully loaded before the code is executed. To ensure that your JavaScript code is loaded synchronously, you can use the defer attribute in your script tag:

The defer attribute tells the browser to continue parsing the HTML while the script is being downloaded, but to only execute the script after the HTML has been fully parsed. This can help ensure that your JavaScript code works consistently, even without opening the developer tools.

3. Caching

Caching can also play a role in this behavior. If your JavaScript file is being cached by the browser, opening the developer tools might trigger a cache refresh, causing the updated code to be loaded. To prevent caching, you can append a query parameter to the URL of your JavaScript file, like this:

By changing the value of the query parameter (e.g., ?v=1), you can force the browser to treat the file as a new resource and fetch it again, bypassing the cache.

Conclusion

In summary, there are a few reasons why JavaScript might only work after opening the developer tools in IE. It could be due to compatibility mode, asynchronous loading, or caching. By using the provided solutions, you can ensure that your JavaScript code works consistently across different scenarios, without the need to open the developer tools.