1. A computer-implemented method, comprising: intercepting, at a proxy server including one or more processors, a request for a source document representing a web page, the request being transmitted from a remote computing device to a remote web server via a network, the request including web browser information indicating web browser software executing on the remote computing device; intercepting, at the proxy server, the source document being transmitted from the remote web server to the remote computing device via the network in response to the request, the source document including a text and specifying one or more fonts in which to display the text; rendering, at the proxy server, the web page using the source document, the web page including the text displayed in the one or more fonts; determining, at the proxy server, unique characters displayed at the web page for each of the specified one or more fonts in which the text is displayed; obtaining, at the proxy server, one or more font subsets based on the unique characters, wherein at least one of the one or more font subsets includes the unique characters in the source document and one or more additional characters related to the unique characters in the source document, and wherein the one or more additional characters related to the unique characters include at least one of (i) one or more characters having a different case than one or more of the unique characters and (ii) one or more characters having a different accent than one or more of the unique characters; determining, at the proxy server, whether the one or more fonts in which the text is displayed form a font family having a plurality of fonts, each of the plurality of fonts having at least one of a different weight and a different style; determining, at the proxy server, whether the web browser software indicated by the web browser information is capable of displaying the font family having the plurality of fonts; and modifying, at the proxy server, the source document by embedding the plurality of fonts therein to obtain a modified source document when the one or more fonts displayed at the web page form the font family having the plurality of fonts and the web browser software indicated by the web browser information is incapable of displaying the font family having the plurality of fonts; and transmitting, from the proxy server to the remote computing device, information specifying the one or more font subsets when the web browser software indicated by the web browser information is capable of displaying the font family having the plurality of fonts, the modified source document, or a command and a single font subset.
1. A computer-implemented method, comprising: intercepting, at a proxy server including one or more processors, a request for a source document representing a web page, the request being transmitted from a remote computing device to a remote web server via a network, the request including web browser information indicating web browser software executing on the remote computing device; intercepting, at the proxy server, the source document being transmitted from the remote web server to the remote computing device via the network in response to the request, the source document including a text and specifying one or more fonts in which to display the text; rendering, at the proxy server, the web page using the source document, the web page including the text displayed in the one or more fonts; determining, at the proxy server, unique characters displayed at the web page for each of the specified one or more fonts in which the text is displayed; obtaining, at the proxy server, one or more font subsets based on the unique characters, wherein at least one of the one or more font subsets includes the unique characters in the source document and one or more additional characters related to the unique characters in the source document, and wherein the one or more additional characters related to the unique characters include at least one of (i) one or more characters having a different case than one or more of the unique characters and (ii) one or more characters having a different accent than one or more of the unique characters; determining, at the proxy server, whether the one or more fonts in which the text is displayed form a font family having a plurality of fonts, each of the plurality of fonts having at least one of a different weight and a different style; determining, at the proxy server, whether the web browser software indicated by the web browser information is capable of displaying the font family having the plurality of fonts; and modifying, at the proxy server, the source document by embedding the plurality of fonts therein to obtain a modified source document when the one or more fonts displayed at the web page form the font family having the plurality of fonts and the web browser software indicated by the web browser information is incapable of displaying the font family having the plurality of fonts; and transmitting, from the proxy server to the remote computing device, information specifying the one or more font subsets when the web browser software indicated by the web browser information is capable of displaying the font family having the plurality of fonts, the modified source document, or a command and a single font subset. 2. The computer-implemented method of claim 1 , wherein the plurality of fonts of the font family include at least two of (i) a normal version of a specific font, (ii) a bolded version of the specific font, (iii) an italicized version of the specific font, and (iv) an underlined version of the specific font.