HTTPS - Wikipedia Jump to content Main menu Main menu move to sidebar hide Navigation Main page Contents Current events Random article About Wikipedia Contact us Contribute Help Learn to edit Community portal Recent changes Upload file Special pages Search Search Appearance Donate Create account Log in Personal tools Donate Create account Log in Contents move to sidebar hide (Top) 1 Overview Toggle Overview subsection 1.1 Usage in websites 1.2 Browser integration 2 Security 3 Technical Toggle Technical subsection 3.1 Difference from HTTP 3.2 Network layers 3.3 Server setup 3.3.1 Acquiring certificates 3.3.2 Use as access control 3.3.3 In case of compromised secret (private) key 3.3.3.1 Certificate revocation 3.4 Limitations 4 History 5 See also 6 References 7 External links Toggle the table of contents HTTPS 57 languages Afrikaans العربية Azərbaycanca Беларуская (тарашкевіца) Беларуская Български বাংলা Català Čeština Dansk Deutsch Ελληνικά Español Eesti Euskara فارسی Suomi Føroyskt Français Gaeilge Galego עברית हिन्दी Hrvatski Magyar Հայերեն Bahasa Indonesia Italiano 日本語 Қазақша 한국어 Lombard Latviešu Монгол မြန်မာဘာသာ Nederlands Norsk bokmål Polski Português Română Русский Srpskohrvatski / српскохрватски Slovenčina Slovenščina Shqip Српски / srpski Svenska தமிழ் ไทย Tagalog Türkçe Українська Oʻzbekcha / ўзбекча Tiếng Việt 吴语 粵語 中文 Edit links Article Talk English Read Edit View history Tools Tools move to sidebar hide Actions Read Edit View history General What links here Related changes Upload file Permanent link Page information Cite this page Get shortened URL Switch to legacy parser Print/export Download as PDF Printable version In other projects Wikimedia Commons MediaWiki Meta-Wiki Wikibooks Wikidata item Appearance move to sidebar hide Checked From Wikipedia, the free encyclopedia (Redirected from HTTP Secure) Page version status This is an accepted version of this page This is the latest accepted revision, reviewed on 5 August 2026. HTTP extension supporting TLS encryption HTTP Persistence Compression HTTPS QUIC Request methods OPTIONS GET HEAD POST PUT DELETE TRACE CONNECT PATCH Header fields Cookie ETag Location HTTP referer DNT X-Forwarded-For Upgrade Response status codes 301 Moved Permanently 302 Found 303 See Other 403 Forbidden 404 Not Found 451 Unavailable for Legal Reasons Security access control methods Basic access authentication Digest access authentication Security vulnerabilities HTTP header injection HTTP request smuggling HTTP response splitting HTTP parameter pollution v t e Internet protocol suite Application layer BGP DHCP (v6) DNS FTP HTTP (HTTP/3) HTTPS IMAP IPP IRC LDAP MGCP MQTT NNTP NTP OSPF POP PTP ONC/RPC RTP RTSP RIP SIP SMTP SNMP SSH Telnet TLS/SSL XMPP more... Transport layer TCP UDP DCCP SCTP RSVP QUIC more... Internet layer IP v4 v6 ICMP (v6) NDP ECN L4S IGMP IPsec more... Link layer ARP Tunnels PPP MAC more... v t e Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP). It uses encryption for secure communication over a computer network, and is widely used on the Internet.[1][2] In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS) or, formerly, Secure Sockets Layer (SSL). The protocol is therefore also referred to as HTTP over TLS,[3] or HTTP over SSL. The principal motivations for HTTPS are authentication of the accessed website and protection of the privacy and integrity of the exchanged data while it is in transit. It protects against man-in-the-middle attacks, and the bidirectional block cipher encryption of communications between a client and server protects the communications against eavesdropping and tampering.[4][5] The authentication aspect of HTTPS requires a trusted third party to sign server-side digital certificates. This was historically an expensive operation, which meant fully authenticated HTTPS connections were usually found only on secured payment transaction services and other secured corporate information systems on the World Wide Web. In 2016, a campaign by the Electronic Frontier Foundation with the support of web browser developers led to the protocol becoming more prevalent.[6] HTTPS has since 2018[7] been used more often by web users than non-secure HTTP, primarily to protect page authenticity on all types of websites, secure accounts, and keep user communications, identity, and web browsing private. Overview [edit] Further information: Transport Layer Security URL beginning with the HTTPS scheme and the WWW domain name label The Uniform Resource Identifier (URI) scheme HTTPS has identical usage syntax to the HTTP scheme. However, HTTPS signals the browser to use an added encryption layer of SSL/TLS to protect the traffic. SSL/TLS is especially suited for HTTP, since it can provide some protection even if only one side of the communication is authenticated. This is the case with HTTP transactions over the Internet, where typically only the server is authenticated (by the client examining the server's certificate). HTTPS creates a secure channel over an insecure network. This ensures reasonable protection from eavesdroppers and man-in-the-middle attacks, provided that adequate cipher suites are used and that the server certificate is verified and trusted. Because HTTPS piggybacks HTTP entirely on top of TLS, the entirety of the underlying HTTP protocol can be encrypted. This includes the request's URL, query parameters, headers, and cookies (which often contain identifying information about the user). However, because website addresses and port numbers are necessarily part of the underlying TCP/IP protocols, HTTPS cannot protect their disclosure. In practice this means that even on a correctly configured web server, eavesdroppers can infer the IP address and port number of the web server, and sometimes even the domain name (e.g. www.example.org, but not the rest of the URL) that a user is communicating with, along with the amount of data transferred and the duration of the communication, though not the content of the communication.[4] Web browsers know how to trust HTTPS websites based on certificate authorities that come pre-installed in their software. Certificate authorities are in this way being trusted by web browser creators to provide valid certificates. Therefore, a user should trust an HTTPS connection to a website when all of the following are true: The user trusts that their device, hosting the browser and the method to get the browser itself, is not compromised (i.e. there is no supply chain attack). The user trusts that the browser software correctly implements HTTPS with correctly pre-installed certificate authorities. The user trusts the certificate authority to vouch only for legitimate websites (i.e. the certificate authority is not compromised and there is no mis-issuance of certificates). The website provides a valid certificate, which means it was signed by a trusted authority. The certificate correctly identifies the website (e.g., when the browser visits "https://example.com", the received certificate is properly for "example.com" and not some other entity). The user trusts that the protocol's encryption layer (SSL/TLS) is sufficiently secure against eavesdroppers. HTTPS is especially important over insecure networks and networks that may be subject to tampering. Insecure networks, such as public Wi-Fi access points, allow anyone on the same local network to packet-sniff and discover sensitive information not protected by HTTPS. Additionally, some free-to-use and paid WLAN networks have been observed tampering with webpages by engaging in packet injection in order to serve their own ads on other websites. This practice can be exploited maliciously in many ways, such as by injecting malware onto webpages and stealing users' private information.[8] HTTPS is also important for connections over the Tor network, as malicious Tor nodes could otherwise damage or alter the contents passing through them in an insecure fashion and inject malware into the connection. This is one reason why the Electronic Frontier Foundation and the Tor Project started the development of HTTPS Everywhere,[4] which is included in Tor Browser.[9] As more information is revealed about global mass surveillance and criminals stealing personal information, the use of HTTPS security on all websites is becoming increasingly important regardless of the type of Internet connection being used.[10][11] Even though metadata about individual pages that a user visits might not be considered sensitive, when aggregated it can reveal a lot about the user and compromise the user's privacy.[12][13][14] Deploying HTTPS also allows the use of HTTP/2 and HTTP/3 (and their predecessors SPDY and QUIC), which are new HTTP versions designed to reduce page load times, size, and latency. It is recommended to use HTTP Strict Transport Security (HSTS) with HTTPS to protect users from man-in-the-middle attacks, especially SSL stripping.[14][15] HTTPS should not be confused with the seldom-used Secure HTTP (S-HTTP) specified in RFC 2660. Usage in websites [edit] As of April 2018[update], 33.2% of Alexa top 1,000,000 websites use HTTPS as default[16] and 70% of page loads (measured by Firefox Telemetry) use HTTPS.[17] As of June 2025[update], 71.2% of the Internet's 150,000 most popular websites have a secure implementation of HTTPS (up from 58.4% in December 2022),[18] However, despite TLS 1.3's release in 2018, adoption has been slow, with many still remaining on the older TLS 1.2 protocol.[19] Browser integration [edit] Most browsers display a warning if they receive an invalid certificate. Older browsers, when connecting to a site with an invalid certificate, would present the user with a dialog box asking whether they wanted to continue. Newer browsers display a warning across the entire window. Newer browsers also prominently display the site's security information in the address bar. Extended validation certificates show the legal entity on the certificate information. Most browsers also display a warning to the user when visiting a site that contains a mixture of encrypted and unencrypted content. Additionally, many web filters return a security warning when visiting prohibited websites. <small>(Using [[Firefox]] as an example)</small>"},"1":{"wt":"File:Extended Validation on Firefox 133 screenshot.webp"},"height":{"wt":"170"},"2":{"wt":"Many web browsers, including Firefox (shown here), use the [[address bar]] to tell the user that their connection is secure, an [[Extended Validation Certificate]] should identify the legal entity for the certificate.\n"},"width":{"wt":"300"},"3":{"wt":"File:HTTPS on Firefox 133 screenshot.webp"},"align":{"wt":"center"},"4":{"wt":"When accessing a site only with a common certificate, on the address bar of [[Firefox]] and other [[Web browser|browser]]s, a \"lock\" sign appears.\n"},"5":{"wt":"File:Self-signed certificate warning on Firefox 133 screenshot.webp"},"6":{"wt":"Most web browsers alert the user when visiting sites that have invalid security certificates.\n"}},"i":0}}]}'>Comparison between different kinds of SSL/TLS certificates (Using Firefox as an example) Many web browsers, including Firefox (shown here), use the address bar to tell the user that their connection is secure, an Extended Validation Certificate should identify the legal entity for the certificate. When accessing a site only with a common certificate, on the address bar of Firefox and other browsers, a "lock" sign appears. Most web browsers alert the user when visiting sites that have invalid security certificates. The Electronic Frontier Foundation, opining that "In an ideal world, every web request could be defaulted to …