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CRT File - What is a .crt file and how do I open it?
Learn about .CRT files and view a list of programs that open them.
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Overview
What is a CRT file? A CRT file is an encoded digital certificate used by a secure website. It identifies the website and verifies its authenticity. CRT files may be saved in a variety of certificate formats, including the Distinguished Encoding Rules ( .DER ) and Privacy Enhanced Mail ( .PEM ) formats.
More Information To host secure websites, web server administrators typically apply for digital certificates from third-party Certificate Authorities, such as GoDaddy, Verisign, or Thawte. These certificates are saved in various formats, including the CRT format. After receiving a certificate, administrators must place it on their web server, within the website they want to secure. When a user accesses the site, the web server passes the certificate to the user's web browser, to verify the site's identity. (If a browser cannot verify a certificate, it may instead show a page that says "This website's certificate is expired.") NOTE: To view the contents of a secure website's digital certificate, click the lock icon that appears in your website's address bar.
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.CRT File Extension
Security Certificate
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What is a CRT file?
A CRT file is an encoded digital certificate used by a secure website. It identifies the website and verifies its authenticity. CRT files may be saved in a variety of certificate formats, including the Distinguished Encoding Rules ( .DER ) and Privacy Enhanced Mail ( .PEM ) formats.
More Information
To host secure websites, web server administrators typically apply for digital certificates from third-party Certificate Authorities, such as GoDaddy, Verisign, or Thawte. These certificates are saved in various formats, including the CRT format.
After receiving a certificate, administrators must place it on their web server, within the website they want to secure. When a user accesses the site, the web server passes the certificate to the user's web browser, to verify the site's identity. (If a browser cannot verify a certificate, it may instead show a page that says "This website's certificate is expired.")
NOTE: To view the contents of a secure website's digital certificate, click the lock icon that appears in your website's address bar.
How to open a CRT file
You can use OpenSSL (multiplatform) to view the contents of a CRT file. For example, if your CRT file contains a certificate saved in the DER format, you can use the following command to view your file's contents:
openssl x509 -inform der -in YourFileName.crt -text -noout
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Programs that open or reference CRT files
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Google Chrome
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Category: Web Files
Updated: October 25, 2023