HTML5 Video File Not Found– New Ways to Solve the Issues

December 12, 2023Jenny Ryan

It is frustrating to see an ‘HTML5 video not Found’ message on your screen. What should be a time to watch an important matter turns to disappointment and confusion. You did your best to find out why the video is not loading on your computer, but even if you find the cause, you can only reach a few solutions. So, this post is here to help you go beyond the most possible and effective ways of fixing the HTML5 errors.

HTML5 Video Not Found

Part 1. Reasons and Solutions for HTML5 Video Not Found

Most of the time, a video can be corrupted by gaining errors from various sources. But there can be many reasons for HTML5, as it is opened using a web browser. With this idea in mind, you have to think about the causes before solving the problems. This part will show the possible causes and, at the same time, the effective methods of repairing HTML5 not working.

With these problems, you can still fix them by following the solutions below:

Update the Browser

It has been said that an updated browser version often solves the issues. Google Chrome, Firefox, Opera, Safari, and Internet Explorer can only play videos with the latest version. If HTML5 is not playing, better check the steps below to update the browser:

Step 1.
From the browser, click the Ellipsis icon from the top right corner. It is also known as Customize and Control Google Chrome. Select the Help option.
Step 2.
Choose the About Google Chrome option from the submenu. The settings will check for the latest updates. If the Update button is available, click on it to install the software. Do the same thing to the other browsers.
Update Browser HTML5 Not Working

Clear the Browser’s Cookies and Cache

Caches and cookies are helpful tools for faster and more efficient online surfing. But over time, without deleting them on your browser, these temporary files will disrupt your online activities, such as HTML5 video not working on your Mac. Follow the instructions on how to delete cookies and cache files:

Step 1.
Access the settings on your browser. From the left pane, find the Advanced section. Click on it.
Step 2.
Choose the Privacy and Security option. When you open the Clear Browsing Data window, choose the files you want to delete. Then, click the Clear Data button to confirm the deletion.
Clear Browser Cookies Cache

Deactivate the Hardware Acceleration

As not all functions are helpful, the Hardware Acceleration can make HTML5 videos not found on your browser. Initially, this function is best for high-resolution graphics for videos and games, but it creates lags for the browser. But don’t worry; turning it off only means the GPU is allowed to load the HTML5 video. You can toggle off the Hardware Acceleration with these steps.

Step 1.
Open the Settings app on your browser via the Ellipsis icon from the upper right corner.
Deactivate Hardware Acceleration
Step 2.
Navigate to the Advanced section and open the System tab. Switch off the button for Use Hardware Acceleration When Available. Try to open the HTML5 video again.

Use HTML5-Supported Codecs

How to fix the video not found issue of HTML5 without changing your settings? You can use codecs that support the video format. However, you will need to contact the browser’s developers and request to install a supporting codec for OGG, WebM, and MP4. This can be an alternative solution, but it is easy to install codecs on the browser, and you might take longer to get an answer from the developers.

Connect to a Stable Internet Network

Your WiFi network will always be an important factor when you want to play HTML5 videos. It is recommended to check the signal stability with a strong signal in your surroundings. Furthermore, do not use mobile data if you barely see any progress on the video. To check the WiFi network, here’s what you need to do:

Step 1.
Go to the Settings app on your device and search for the Network & Settings menu.
Check Internet Network HTML5 Video Not Playing
Step 2.
Once the window is opened, click the Status button under the Network Status section. Check if the solid bars are high on numbers. This means the signal has good strength.

Part 2. Repair Saved HTML5 Video Not Playing

What if the video is unplayable from the start? Because of corrupted details, the playback is interrupted on your device. Aiseesoft Video Repair is the recommended solution to remove the errors in your video. The cross-platform software intends to repair the video quality, resolution, frame rate, and other elements to revive the video playback. While it has intelligent technology that can imitate a perfect sample video, the interface is made to be beginner-friendly for an easier learning curve. On top of these, Video Repair has the highest rate of successfully fixing corrupted HTML5 files on Windows or Mac.

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Step 1.
Download Aiseesoft Video Repair by clicking the Free Download button. Follow the onscreen instructions to install the software completely. Then, wait until the program is running on your computer. Click the + button to upload the corrupted file. Proceed by clicking the Open button.
Video Repair Download Plus Upload
Step 2.
Click the + button on the right. It is recommended that the sample video should consist of the same details as the corrupted video, including the encoder, duration, and resolution. It will get a higher chance of better results.
Aiseesoft Upload Sample Video
Step 3.
After the preparation, initiate the process by pressing the Repair button. Wait for the program to process and recover the video. After a while, the corrupted video is fixed. Check for mismatches from the corrupted and sample video.
Video Repair Process Mismatch
Step 4.
Preview the result by using the Preview option. If you like the result, you can export the file by clicking the Save button. Once done, you can do another video repair by clicking the Upload Other Videos button.
Video Preview Save Repair Other Videos

Part 3. FAQs about HTML5 Video Not Playing

Is HTML5 still a thing?

Yes. It is widely used for web designing and applications. It is still supported by modern browsers, and using it is not impossible. However, it will require more help from technologies like CSS, Javascript, and so on.

How do I fix the HTML5 video 4 error?

When you see the ‘Error code: html5_video:4 message,’ you may need to check the supported codec on your browser. It is also best to keep the browser updated, as the older version does not support HTML5. Additionally, use the solutions from this article to quickly fix the problem.

Does Firefox support HTML5?

Yes. But keep in mind Mozilla Firefox Version 2 to 20 partially supports HTML5. This means there is no assurance that the video will play on the browser. But if it’s updated to Version 49 and above, playing a video will not be impossible.

Is it possible to convert HTML5 to other video formats?

There are tools available to convert HTML to a different format. One of these converters is FFmpeg, which you can install as a server on your browser. Another one is, which creates a background task that uses MEdiaToolkit. Then, it will easily convert HTML5 to MP4, WebM, and OGG.

Is there a way to play HTML5 video on my computer?

There are video player alternatives that support the video format. Try VPlayed, Kaltura, Brid.TV, Flow Player, VideoJS, Muvi, Dacast, JW Player, THEOPlayer, and more. Take note that most of these alternatives are not for free and require a complex setup.


To summarize this article, you have learned what ‘HTML5 video not found’ means on your browser. You also discovered the best solutions to fix the issues from the browser, unsupported codec, and unstable internet connection. If the HTML5 video turns out to be corrupted, it is not a problem with Aiseesoft Video Repair because of its powerful system. You can try it for free and see how it can turn a corrupted file into a brand-new and high-quality video.

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