Top "If-modified-since" questions

Why am I getting "(304) Not Modified" error on some links when using HttpWebRequest?

Any ideas why on some links that I try to access using HttpWebRequest I am getting "The remote server returned …

http httpwebrequest http-status-code-304 if-modified-since

Understand If-Modified-Since HTTP Header

I am looking at a Caching library that is trying to use the If-Modified-Since header of a request object. The …

php http cache-control outputcache if-modified-since

how does a etag work in expressjs

Expressjs automatically send etags. I would like to know how the etag is generated..is it based on the content …

express cache-control etag if-modified-since

Handling If-modified-since header in a PHP-script

I have a PHP script which is called with an ?img= parameter. The value for that parameter is an (urlencoded) …

php if-modified-since

Chrome - why is it sending if-modified-since requests?

I have a page with lots of small images (icons). When used with chrome, each time the page is reloaded, …

http caching google-chrome if-modified-since

(Weak) ETags and Last-Modified

As far as I understand the specs, the ETag, which was introduced in RFC 2616 (HTTP/1.1) is a successor (of sorts) …

http last-modified etag if-modified-since

Chrome doesn't send "If-Modified-Since"

I want browsers to always add (except first time) "If-Modified-Since" request header to avoid unnecessary traffic. Response headers are: Accept-Ranges:…

http if-modified-since

detect if a web page is changed

In my python application I have to read many web pages to collect data. To decrease the http calls I …

python web screen-scraping if-modified-since