In the Hypertext Transfer Protocol (HTTP), HTTP header fields contain the operating parameters of an HTTP request or response. With the request or response line (first line of message), they form the message header.

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19 views

Can servers ever return headers not beginning with HTTP?

When I checked URLs for headers, they always start with HTTP. For example, HTTP/1.1 301 Moved Permanently. If I remember, I think in the past, headers started with Status: followed by a code. ...
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70 views

How to serve for International Googlebots if we redirect users to subdomains for language matching?

So, we have a site and a few sub-domains with content in different languages and we're using Hreflang and canonical implementations for SEO. We do detect the language that users use in their browsers ...
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2answers
36 views

HTTP Header broken? Browsers don't open our pdf, but open all other pdfs

My Firefox and Chrome usually open PDF files very nicely, without asking and within the browser window. When clicking on a link to a PDF on our own website: Firefox asks if it should download them, ...
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27 views

Eliminating 'cookie' from 'vary:' without breaking website functionality

I read that some middle-man servers won't cache websites that have cookie set in the vary: header. For example, If my website issues a vary:accept-encoding,cookie as opposed to vary:accept-encoding ...
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1answer
25 views

Is it okay for url to end .html even if stored gzipped?

I have some html files stored on Amazon s3, some are quite large so the plan was to store them gzipped and return that as the encoding type when receive a request for them, is that how it works rather ...
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2answers
66 views

When do browsers clear cache and how can I make more use of 304 responses?

I have a website with some some content which changes frequently. I would like to benefit from good caching when this doesn't change (so would ideally use a longer Cache-Control header), but would ...
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1answer
22 views

Trying to understand cache control actions observed on my site

While working on some optimizations for my site, I noticed some things in Networking Timings for Chrome Developer Tools differ from those in Firefox Developer Tools. Very consistently Chrome loads a ...
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1answer
42 views

Vary: User-Agent in case of redirect?

Should we use Vary: User-Agent in our headers when the regular url www.mydomain.com is forwarded to m.mydomain.com? Or is it not needed for Google due the redirect?
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1answer
54 views

Earliest browsers that support if-modified-since or if-none-match headers

Based on my observations, google and probably many others are in love with websites that include the Etag and Last-modified headers along with the if-modified-since and if-none-match header checking ...
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2answers
46 views

Caching a changing site

I run a website where the static content changes at least 4 times a week and I'm trying to figure out the best header arrangement to use. Currently I have all caching related headers in use. I have ...
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1answer
48 views

Trying to add cache header to 301 pages made by ModRewrite

I have several URLs on my website that get redirected to other URLs using Mod-Rewrite. For example: RewriteRule ^section$ /newsection [NC,L,R=301] The above rule redirects ...
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187 views

If I only serve gzipped version of my content, should I add the vary accept encoding header?

I just moved a static site from a VPS to Amazon S3. I have decided to serve only gzipped version of my pages, since S3 is not a webserver I can't have logic based on headers. I also use Cloudfront as ...
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103 views

X-Robots-Tag: noindex on an HTTP 302 response to remove subdomain

This very related to this question "X-Robots-Tag: noindex" on an HTTP 301 response, however I don't see a definitive answer. We have subdomains we use for our affiliate links, the ...
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2answers
35 views

What is the proper response header when an address is not available but its parent is available and is displayed?

My website addresses has a hierarchy structure. When one page is requested, and it is not a valid address, it tries to find its parent, and if the later exists, it will show it. Now, my question is ...
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3answers
324 views

How should an expired content be handled?

Let's imagine this simplified case: An auction website has "auction detail" pages. A few weeks after the auction is over, the "auction detail" page is no more available. We are simply serving a ...
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1answer
211 views

Trailing slash on Root folder - Is it possible to remove it without 301?

I have noticed something very strange on the site I'm working on. We currently only show http://www.example.com. The URL http://www.example.com/ (slash at the end) gets 301ed to ...
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2answers
23k views

Font blocked from loading by Cross-Origin Resource Sharing policy: No 'Access-Control-Allow-Origin'

we are experiencing this error in Google Chrome. We thought everything was set-up correct. But maybe not? Font from origin http://skin.cdn.com has been blocked from loading by Cross-Origin ...
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2answers
767 views

CloudFlare Not Sending If-Modified-Since Headers

I'm trying to reduce my server load by providing 304 Not Modified responses for content where appropriate. CloudFlare is my middle man, so they should be sending If-Modified-Since headers whenever a ...
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0answers
253 views

Apache 404 Issue after upgrading from Mavericks to Yosemites

Good afternoon fellow StachExachangers, Background story: I have recently upgraded my macbook pro from Mavericks to Yosemites, everything went well except my local development environment got ...
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1answer
1k views

Caching of JS and CSS files – Apache mod_headers doesn’t take effect

As suggested by an answer on SO, I'm trying using a version number on my JS and CSS files so that the browser will only make a request when the JS or CSS version number is changed in my PHP file. To ...
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1answer
34 views

Does referrer header checking offer any real world security improvement?

At work we use a central portal that provides basic SSO functionality to other applications. In addition to verifying the SSO data sent, all of our existing in-house applications (used by the public) ...
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1answer
120 views

Did I use the proper way to remove pages from Google Webmaster Tools forever?

I have many pages from one year ago that were deleted and are returning a 404 error code, but two week ago after I cleared the content of my robots.txt, the errors in my Google Webmaster Tools reports ...
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2answers
373 views

Redirect to an affiliate using PHP or JavaScript redirect?

I was asked to introduce a unified self hosted URL-Shortener/Forwarder/Tracking Service for an website that earns money from affiliates. One example I found was one of the bigger german sites for ...
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1answer
167 views

Use different .htaccess file based on set header from browser

I want to have the ability to test .htaccess rules before saving them to the main .htaccess file. Is it possible to set a specific request header and have Apache use a set of rules from a different ...
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1answer
39 views

What is best practice for search engines when a website is under maintenance?

I need around a week to transition a heavily data-driven website from one back end to another. During that time I do plan to attempt to keep some pages live, but they won't all work well or look ...
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853 views

How to get keywords from Google HTTP referrer?

Can the http referrer URL from Google be decoded so that I can see the specific keywords? ...
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41 views

Can serving a different header code for crawlers and users be considered cloaking?

I have urls that point to pages I don't know yet if exist. Whenever reaching those, I perform a not-so-quick external sources check, and if exists generate the page on the fly. In order to avoid this ...
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1answer
787 views

Can I set Cache-Control in the .htaccess file for a specific part of a document (just a section of the <body>)

I noticed, by using Google Page Speed Insights, that if I structure my HTML to load the critical, above-the-fold content first, my page will improve performance - and it woks (with now current perf. ...
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1answer
2k views

Is it necessary to specify content-type in http response header?

Except for the html document, currently all the files (css, javascript and images) served from my web server do not specify the content-type in the http response header. I happen to notice this as I ...
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2answers
362 views

Why doesn't this web crawler obey requests to stop crawling my pages?

I have a hidden page that verifies internal payments from PayPal. The page has the following in its HTTP headers: X-Robots-Tag: noindex, nofollow But once in a while I see this in the page logs: ...
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305 views

Why is “29030400” seconds used as a common value for cache expiration?

I noticed that 29030400 is used very often in the Expires directives for static files. Google recommends to cache this kind of files up to 1 year (1 month at least). I did the math: 29030400 seconds ...
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1answer
283 views

Should we allow HEAD requests?

Our web application is predominantly read-only. As such we only allow GET requests. However, we regularly get errors in our logs because of user agents making HEAD requests. I've seen these come from ...
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1answer
274 views

Can a past Expires header value cause a site to not be indexed by Google?

I'm using this: <filesMatch "\.(html|htm|js|css)$"> FileETag None <ifModule mod_headers.c> Header unset ETag Header set Cache-Control "max-age=0, no-cache, no-store, ...
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1answer
238 views

how do we organize our site's (navigation) pages in Google search? [duplicate]

Is there a HTML technique for organizing my site's main pages in Google (navigation)? Or is it made by a Google's specific tool for creating a result layout like in this picture? Look at the ...
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1answer
3k views

IP Address headers (Remote_Addr) - When is this header sent by the browser?

I want to know when a browser includes the header - Remote_Addr in the HTTP request. I observed the request sent by the browser on loading stackoverflow.com, in the web console window of Firefox. ...
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1answer
522 views

Nginx Browser Caching using HTTP Headers outside server/location block

I am having difficulty setting the HTTP expires headers for Nginx outside of specific server (and then location) blocks. What I want is to something like the following: location ~* ...
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2answers
2k views

Is no cache meta tag bad for performance?

I see many websites, seemingly arbitrarily adding the no cache meta tag on every page. Like this: <META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE"> <META HTTP-EQUIV="CACHE-CONTROL" ...
5
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1answer
659 views

How do Expires headers and cache manifest rules work together?

I find the W3C's official Offline Web Applications specification to be rather vague about how the cache manifest interacts with headers such as ETag, Expires, or Pragma on cached assets. I know that ...
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1answer
238 views

HTTP Headers caching

I am not totally sure bout HTTP headers, but from what I read its good to have some level of caching on static pages also I am not sure if Transfer Encoding: chunked is a good thing. I was not finding ...
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1answer
152 views

What's the best HTTP code for dynamically deleted pages?

I've built my own CMS and I'm looking for the best way to handle pages / items deletion. Actually, pages and items were deleted and cannot be restored. But since I have implemented a bin, I don't ...
2
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1answer
106 views

How to configure apache2 to just save certain POST requests without even passing them to application?

I'm running Apache in front of glassfish server using BalancerMember. For performance reasons I would like that POST requests on certain endpoint are just saved to a file without passing them to ...
2
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1answer
72 views

Why was 303 skipped in HTTP/1.0?

While looking back over HTTP response codes today I noticed that the 301, 302, and 304 response codes were defined in HTTP/1.0 but not the 303 response code. Does anyone know why the number 303 was ...
7
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1answer
151 views

Does the SPDY protocol eliminate the need for cookieless domains?

With plain HTTP, cookieless domains are an optimization to avoid unnecessarily sending cookie headers for page resources. However, the SPDY protocol compresses HTTP headers and in some cases ...
2
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1answer
3k views

Google Chrome audit: resources are explicitly non-cacheable?

If I run a Google Chrome audit on a site, it lists all CSS, PNG, JPG, JS files and even the main domain (i.e. www.example.com) under the heading: Leverage browser caching The following resources ...
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4answers
2k views

How to tell the Browser the character encoding of a HTML website regardless of Server Content-Type Header?

I have a HTML page that correctly (the encoding of the physical on disk matches it) announces it's Content-Type: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> ...
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2answers
1k views

How to extract AdWords keywords from incoming traffic?

I have a landing page in which I need to understand what keywords are coming in from AdWords and then display some information based on this. I am not certain, but I don't believe that this ...
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3answers
1k views

What does it mean when a User-Agent has another User-Agent inside it?

Basically, sometimes the user-agent will have its normal user-agent displayed, then at the end it will have the "User-Agent: " tag displayed, and right after it another user-agent is shown. Sometimes, ...
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1answer
4k views

HTTP Header Cache Time: s-maxage and max-age

I am setting up a CDN for my website, I found the following sample for adding to the 'httpd.conf' file, this is used to adjust the cache-time for client and CDN: ExpiresActive On ExpiresByType ...
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3answers
360 views

PHP Include meta tags

A website I'm currently working on is http://www.troubi.com . Please don't care to look at the source code. If I validate the website through the w3cValidator a lot of errors occur all due to ...
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2answers
301 views

What should happen when content is deleted?

I am wondering about the standard handling of deleted data links from an application and an SEO perspective. I have an application where users can create content but they can also delete content. ...