How can I change the max length of the drupal 7 signature field to more than 255 characters? I've already changed the sql data type from 255 to varchar(900), yet drupal still shows the error, as soon as a user wants to update his signature to more than 255 characters.

2 Answers 2


In a mysql database varchar can only store 255 characters.

  • Nope. It can store more. I've changed it to 900 and manually entered a siganture longer than 255 Characters into the MySQL signature field of a certain user - worked without a problem. Also, changing the data type from varchar to another didn't help either, it was still limited to 255 in Drupal.
    – and93hil
    Feb 15, 2018 at 7:27
  • WOW I feel old. You are right. "Values in VARCHAR columns are variable-length strings. The length can be specified as a value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions. The effective maximum length of a VARCHAR in MySQL 5.0.3 and later is subject to the maximum row size (65,535 bytes, which is shared among all columns) and the character set used." Feb 15, 2018 at 14:15

I know this isn't the case but you can look around the module(code) and do this but you are on your own ,, because its dangerous

enter link description here

This module allows you to change (uneditable) settings for fields.

READ WITH CAUTION: Please don't use this module unless you know what the hell is this module does which I'm NOT sure about 100% ,, so I'd recommend using it in stage/dev/local environment until you are sure about it

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