How should I configure If-Modified-Since on database-driven pages?

Following your interview with Eric Enge - you mention about "If Modified-Since." We worked on many websites whereby the actual file timestamp doesn't change but the content does as the pages are database-driven. How should we deal with such situations?

Tommo, London, UK

Category:

Science & Technology

Tags:

• google
• seo
• if-modified-since

[theylmdl]

Actually, "If-Modified-Since" ist part of the client's request header and the server's response should be in the "Last-Modified" key.

[lillmii3o]

Thanks for your wonderful answers in all videos. Really appriciated!

[nickstout513]

This is a "tasteful" video. =p

[olbywong717c]

This video went viral on Albania

[tamekawelle]

great clip .. keep it up thanks



[SebastianXgib]

For a comprehensive tutorial with ready-to-use PHP code lookup Sebastian's Pamphlets, or query Google for [Save bandwidth costs: Dynamic pages can support If-Modified-Since too].

[kron3r]

Yeah, what @NoirNG said.

[NoirNG]

@kron3r Nonono... the header your server is sending is Last-Modified. The request made by the client may be conditional: if the request contains the If-Modified-Since header AND the modification timestamps are equal (= no modification, since client has the current version), your server should respond with "304 Not Modified" and NOT send the body.

If the condition is not met (= your server has different timestamp), the body is transferred as if no conditional request was made.

[NoirNG]

@kisvarosipari web-sniffer (DOT) net - Look for the Last-Modified header in the response. If it exists, click on the date. If it shows 304 Not Modified, then everything works perfectly.

[kisvarosipari]

how can we know wether or not our web page has if-modified-since so that we update it or it has not so that we let the google crawl it without changing it.