I used this in twig :
{{ form_start(form, { 'attr': {'autocomplete': 'off'} })  }}
and this in the controller action :
'attr'=>array('autocomplete' => 'off'
But the autocomplete still not disabled!!!!
I used this in twig :
{{ form_start(form, { 'attr': {'autocomplete': 'off'} })  }}
and this in the controller action :
'attr'=>array('autocomplete' => 'off'
But the autocomplete still not disabled!!!!
 
    
    UPDATE:
If you are using symfony 4 the proper way is using off
'attr'=>['autocomplete' => 'off']
 
    
    You can use :'attr' => ['autocomplete' => 'disabled']
 
    
     
    
    For choiceType field, use:
'choice_attr' => function($choice, $key, $value) {
    return ['autocomplete' => 'off'];
}
Source: https://symfony.com/doc/current/reference/forms/types/choice.html#choice-attr
