RSA Encrypt/DecryptEncrypt and decrypt using RSA public-key cryptography.

RSA Encrypt/Decrypt
Encrypt and decrypt using RSA public-key cryptography.
Enter Input
Type or paste your input.
View Output
Results appear in real time.
Copy Result
Click Copy to copy the output.
What Is RSA Encrypt/Decrypt?
RSA uses public key for encryption, private key for decryption. RSA-OAEP via Web Crypto API provides semantic security. Max plaintext ~190 bytes for 2048-bit/SHA-256. For larger data, use hybrid encryption. All in browser.
Why Use Our RSA Encrypt/Decrypt?
- Fast, accurate processing
- 100% client-side — data never leaves your browser
- Free online tool with no signup required
- Mobile-friendly with 44px touch targets
Common Use Cases
Development
Use in software development workflows.
Security
Cryptographic and security applications.
Education
Learn about algorithms and techniques.
Verification
Verify and validate data integrity.
Technical Guide
C = M^e mod n. D = C^d mod n. RSA-OAEP adds randomized padding via MGF1/SHA-256 for IND-CCA2 security. Max: keyLength - 2*hashLength - 2. Web Crypto importKey then encrypt/decrypt.
Tips & Best Practices
- 1All processing happens in your browser
- 2Results are deterministic for the same input
- 3Use Copy button to quickly grab output
- 4Works on mobile devices with touch-friendly interface
Related Tools

SHA-256 Hash Generator
Generate SHA-256 hash digests.

MD5 Hash Generator
Generate MD5 hash digests.

AES Encrypt/Decrypt
Encrypt and decrypt text using AES with a passphrase.

Base64 Encode
Encode text to Base64 format instantly in your browser.

Base64 Decode
Decode Base64-encoded strings back to plain text instantly.

Base64 Image Encoder
Convert images to Base64-encoded data URIs for embedding in HTML and CSS.
Frequently Asked Questions
QIs this tool free?
QIs my data secure?
QDoes it work on mobile?
QWhat browsers are supported?
QCan I use this offline?
About RSA Encrypt/Decrypt
RSA Encrypt/Decrypt 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.







