How to fix “Headers already sent” error in PHP

Question

When running my script, I am getting several errors like this:

Warning: Cannot modify header information 
- headers already sent by (output started at /some/file.php:12) 
in /some/file.php on line 23

The lines mentioned in the error messages contain header() and setcookie() calls.

What could be the reason for this? And how to fix it?

before header() no output will be echo it means all echo statment in above header remove it — wild, Feb 18 '14 at 07:14
Just type “Headers already sent” in google and click search — Prasanth Bendra, Feb 18 '14 at 07:17
http://stackoverflow.com/questions/8028957/how-to-fix-headers-already-sent-error-in-php/8028987#8028987 — Prasanth Bendra, Feb 18 '14 at 07:19
http://stackoverflow.com/questions/8028957/how-to-fix-headers-already-sent-error-in-php — Prasanth Bendra, Feb 18 '14 at 07:19
There should be no text before header line not even space. Also writing html code below php code prevets these types of erros. — Rolen Koh, Feb 18 '14 at 07:30
can you post here code of line 12 and 23. (if your issue still exists) — Maz I, Feb 18 '14 at 07:33

score 1 · Accepted Answer · answered Feb 18 '14 at 07:23

This type of problem is caused when you use header after you write in your page. I assume you code might look like ::

 <html>
   <head>
     <title> title </title>
     .........
   </head>

   <body>
    .....
     <?php 
        header() // checking some header
     ?>
     .....
   </body>
 </html>

If so, use header() before html or any kind of echo or writing code. But this is not correct solutions. You can use ob_start. This is the best solution. check this

How to fix “Headers already sent” error in PHP

1 Answers1