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Online JavaScript Validator

To use this free online JavaScript validator, enter your code into the box below and click the green validate button.

What is this tool?

It is a simple online JavaScript validator that you can use to find syntax errors and mistakes in your code and get suggestions for improving it.

To start using this tool simply paste your JavaScript into the editor, or use the "choose a file" option to upload a .js or .txt file from your local machine. Then click "validate" and if any errors or improvement opportunities are found they will be shown in sequential order e.g.

The validation error above is typical of what you will see. From left to right you have the number of the error in the list, what line and what column it is on in the code, what the error is; In this case, it is an unclosed string. Lastly, there is a bit of the erroneous code shown to further aid you in identifying where the problem is.

Once you have finished fixing JavaScript validation errors you can download a .js file with your edited code using the "download" option.