Last-Modified

A linha de cabeçalho Last-Modified do cabeçalho de resposta HTTP contém a data e a hora em que o servidor de origem acredita que o recurso foi modificado pela última vez. É usado como um validador para determinar se um recurso recebido ou armazenado é o mesmo. Menos preciso do que um cabeçalho ETag, é um mecanismo de retorno. Os pedidos condicionais If-Modified-Since or If-Unmodified-Since fazem uso deste campo.

Header type Response header
Forbidden header name no
CORS-safelisted response-header yes

Syntax

Last-Modified: <day-name>, <day> <month> <year> <hour>:<minute>:<second> GMT

Directives

<day-name>
One of "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", or "Sun" (case-sensitive).
<day>
2 digit day number, e.g. "04" or "23".
<month>
One of "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" (case sensitive).
<year>
4 digit year number, e.g. "1990" or "2016".
<hour>
2 digit hour number, e.g. "09" or "23".
<minute>
2 digit minute number, e.g. "04" or "59".
<second>
2 digit second number, e.g. "04" or "59".
GMT

Greenwich Mean Time. HTTP dates are always expressed in GMT, never in local time.

Examples

Last-Modified: Wed, 21 Oct 2015 07:28:00 GMT 

Specifications

Specification Title
RFC 7232, sessão 2.2: Last-Modified Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Last-ModifiedChrome Full support YesEdge Full support YesFirefox Full support YesIE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes

Legend

Full support  
Full support

See also