Extract text from digital certificates (DER)
To convert DER certificates to another format, you need OpenSSL or other Encoded software.
To convert other file formats to the "Binary Digital Certificate" file type, you need software like OpenSSL or a similar tool.
A .DER file stores a digital certificate or cryptographic key in a binary format. It relies on the ASN.1 standard and uses Distinguished Encoding Rules. Organizations primarily use these files for X.509 public key infrastructure, often within Java platforms or legacy network appliances. IT professionals typically handle these files using OpenSSL or native operating system certificate managers.
The main disadvantage of the .DER format is its binary structure. You cannot open it in a standard text editor to read the issuer details, expiration dates, or copy the certificate block. This makes troubleshooting difficult. Furthermore, most modern web servers, such as Nginx and Apache, do not accept .DER files natively in their configuration. They require plain-text, Base64-encoded formats instead.
To make this file usable across different systems, you must convert it. For web server configuration, convert .DER to PEM or CRT. For archiving or importing into Windows server environments, convert it to PFX or P12, which can also bundle the private key. Drop your file here to analyze and convert it securely right in your browser - free, online, and without installing software.
Convert.Guru analyzes your DER file, detects the exact format, and lets you read the text inside.
Users also converted CER, PEM, CRT, CERT, TXT, ZIP, PDF, DAT, INDD, BIN, ASPX, P7B and JKS files.
If you want to convert DER file to PEM, CER, JKS, HTML, HTM, CSS, JS, PHP, ASP, ASPX, JSP or JSPX, you can use OpenSSL or similar software from the "Digital Certificate Storage" category. In the File menu, look for Save As… or Export….
To convert RSS, CSS, CGI, SITEMAP, PL, WEBMANIFEST, JSON, JS, XML, HTML, ICO or HTM files to DER, try OpenSSL or another comparable tool in the "Digital Certificate Storage" category.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our DER converter.