How to get the browser to cache images, with PHP?

by

First of all, if you’re using sessions, you must disable session_cache_limiter (by setting it to none or public). Headers it sends are pretty bad for caches.

session_cache_limiter('none');

Then send Cache-Control: max-age=number_of_seconds and optionally an equivalent Expires: header.

header('Cache-control: max-age=".(60*60*24*365));
header("Expires: '.gmdate(DATE_RFC1123,time()+60*60*24*365));

For the best cacheability, send Last-Modified header and reply with status 304 and empty body if the browser sends a matching If-Modified-Since header.

header('Last-Modified: '.gmdate(DATE_RFC1123,filemtime($path_to_image)));

For brevity I’m cheating here a bit (the example doesn’t verify the date), but it’s valid as long as you don’t mind browsers keeping the cached file forever:

if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
   header('HTTP/1.1 304 Not Modified');
   die();
}

More Related Contents:

  1. How to provide dynamic HTML in PHP?
  2. Get img src with PHP
  3. Can I embed a .png image into an HTML page?
  4. How to embed images in html email
  5. How to add text to an image with PHP GD library
  6. php link to image file outside default web directory
  7. Send email with PHPMailer – embed image in body
  8. How to embed images in a single HTML / PHP file?
  9. How to display an BLOB image stored in MySql database?
  10. Hiding a Div using php
  11. Convert HTML to Image in PHP without shell
  12. Route to image in Laravel [closed]
  13. Create hyperlink from html table row to open record on a new page
  14. How to minify php page html output?
  15. How to upload images into MySQL database using PHP code
  16. Merging two images with PHP
  17. How do I get the HTML code of a web page in PHP?
  18. What is causing “Unable to allocate memory for pool” in PHP?
  19. How to import/include a CSS file using PHP code and not HTML code?
  20. How to force a file to download in PHP
  21. Remove all the line breaks from the html source
  22. PHP: iPad does not play MP4 videos delivered by PHP, but if accessed directly it does
  23. php resize image on upload
  24. Getting node’s text in PHP DOM
  25. How to display XML in HTML in PHP?
  26. PHP simple foreach loop with HTML [closed]
  27. Count and limit the number of files uploaded (HTML file input)
  28. PHP $_POST not working? [duplicate]
  29. Conditional Statements in PHP code Between HTML Code
  30. PHP – Create simple animated GIF from two JPEG images? [closed]

Leave a Comment