Self-Signed Certificate GeneratorGenerate self-signed SSL/TLS certificates for development.
Self-Signed Certificate Generator
Generate self-signed SSL/TLS certificates for development.
Domain
e.g. localhost.
Validity
Period and key size.
Generate
Create cert and key.
What Is Self-Signed Certificate Generator?
Self-signed certs are signed by the creator, not a CA. Ideal for development and testing. Generates RSA key pair and certificate with configurable validity. For production, use Let's Encrypt.
Why Use Our Self-Signed Certificate Generator?
- Quick dev certs
- Configurable validity
- Cert and key together
- 100% client-side
Common Use Cases
Local Dev
HTTPS localhost.
Testing
SSL/TLS config.
Internal
Encrypt services.
Learning
Cert structure.
Technical Guide
RSA RSASSA-PKCS1-v1_5/SHA-256. Certificate with subject CN, issuer (self), validity dates. PEM export.
Tips & Best Practices
- 1Dev only
- 2Let's Encrypt for production
- 3365 days common
- 4Keep key secure
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Encoding & CryptoFrequently Asked Questions
QFree?
QTrusted?
QKey safe?
QProduction?
QSizes?
About Self-Signed Certificate Generator
Self-Signed Certificate Generator is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.