Convert SSL Certificates Between PEM, PFX, DER & P7B Formats
Convert SSL certificates between standard formats: PEM and PFX/PKCS#12. Essential for migrating certificates between IIS (Windows) and Apache/Nginx (Linux) servers.
📖 Learn more: Converting between PEM, PFX, and other SSL formats
Convert SSL Certificate
Supported Certificate Formats
📄 PEM (Privacy Enhanced Mail)
File Extensions: .pem, .crt, .cer, .key
Encoding: Base64 ASCII
Common Use: Apache, Nginx, most Linux servers
Format: Text file with BEGIN/END markers
-----BEGIN CERTIFICATE----- MIIDXTCCAkWgAwIBAgIJAKL0UG... -----END CERTIFICATE-----
🔐 PFX/PKCS#12 (Public Key Cryptography Standards #12)
File Extensions: .pfx, .p12
Encoding: Binary
Common Use: Windows IIS, Microsoft servers
Features: Can contain certificate, private key, and entire chain in one file. Usually password-protected.
🔒 DER (Distinguished Encoding Rules)
File Extensions: .der, .cer
Encoding: Binary
Common Use: Java platforms
Features: Binary format of PEM certificate
📦 P7B/PKCS#7
File Extensions: .p7b, .p7c
Encoding: Base64 ASCII
Common Use: Windows, Java Tomcat
Features: Can contain certificate and chain, but NOT the private key
Common Conversion Scenarios
🔄 PEM to PFX (Apache/Nginx to IIS)
Use Case: Migrating from Linux Apache/Nginx server to Windows IIS
Requirements: Certificate file, private key file, optional intermediate certificates
Result: Single .pfx file with password protection
🔄 PFX to PEM (IIS to Apache/Nginx)
Use Case: Migrating from Windows IIS to Linux Apache/Nginx
Requirements: PFX file and password
Result: Separate certificate and private key files
🔄 DER to PEM (Java to Apache)
Use Case: Converting Java certificates to Apache format
Requirements: DER certificate file
Result: PEM formatted certificate
🔄 PEM to DER (Apache to Java)
Use Case: Converting Apache certificates to Java format
Requirements: PEM certificate file
Result: DER binary certificate
How to Convert SSL Certificates
- Select Source Format: Choose the format you're converting FROM
- Select Target Format: Choose the format you're converting TO
- Choose Input Method: Either paste the certificate text or upload a file
- Add Password (if needed): For PFX files, enter the password
- Click Convert: Click the "Convert Certificate" button
- Download Result: Download your converted certificate
⚠️ Security Note: Your certificates and private keys are processed in real-time and are NOT stored on our servers. For maximum security, consider using OpenSSL command-line tools for production environments.
OpenSSL Command-Line Alternatives
For advanced users, here are OpenSSL commands for common conversions:
PEM to PFX
openssl pkcs12 -export -out certificate.pfx -inkey privatekey.key -in certificate.crt -certfile ca-bundle.crt
PFX to PEM
openssl pkcs12 -in certificate.pfx -out certificate.pem -nodes
DER to PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem
PEM to DER
openssl x509 -outform der -in certificate.pem -out certificate.der
Frequently Asked Questions
How do I convert PEM to PFX?
Select Standard PEM as the source and PKCS#12 (PFX/P12) as the target. Paste your certificate and private key, set a password, and click Convert Certificate.
What's the difference between PEM and PFX?
PEM is a text-based format commonly used on Linux/Apache servers, while PFX is a binary format used on Windows/IIS servers. PFX can contain the certificate, private key, and chain in one password-protected file.
Can I convert a certificate without the private key?
You can convert the certificate itself between formats (PEM ↔ DER ↔ P7B), but to create a PFX file, you need both the certificate AND the private key.
Why do I need to convert SSL certificates?
Different servers and applications require different certificate formats. For example, Apache uses PEM, IIS uses PFX, and Java uses DER or JKS.
Is it safe to upload my private key?
While our tool processes everything in real-time without storage, we recommend using command-line tools (OpenSSL) for production certificates with private keys for maximum security.