This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

How do I remove the 10000 char limit for alert boxes?

  • 1 reply
  • 9 have this problem
  • 1 view
  • Last reply by phihag

more options

I am a web developer professionally, and I tend to use Firefox alert boxes as a quick easy way to debug JSON data, because Firefox seems to have the only alert box that allows selection/copying. (Alert the JSON data, copy it and paste it into jsonlint.com to get a detailed error message, rather than the default "JSON.parse" error).

With Firefox 5, I noticed that the alert box now seems to be limited to 10000 characters where it wasn't before (This may have actually happened in 4, they came out in such rapid succession, it's hard to tell).

This makes it more difficult to troubleshoot. Is there something I can change in about:config to either remove the 10000 character limit or at least set it to something a bit more usable?

I am a web developer professionally, and I tend to use Firefox alert boxes as a quick easy way to debug JSON data, because Firefox seems to have the only alert box that allows selection/copying. (Alert the JSON data, copy it and paste it into jsonlint.com to get a detailed error message, rather than the default "JSON.parse" error). With Firefox 5, I noticed that the alert box now seems to be limited to 10000 characters where it wasn't before (This may have actually happened in 4, they came out in such rapid succession, it's hard to tell). This makes it more difficult to troubleshoot. Is there something I can change in about:config to either remove the 10000 character limit or at least set it to something a bit more usable?

All Replies (1)

more options

Instead of using alert, use firebug's console.log to output large amounts of data.