RSA & PEM Tools

Generate keys, encrypt, decrypt, sign, verify.

How RSA works

RSA uses a key pair. The public key can be shared; the private key must stay secret.

Encryption: anyone encrypts with the public key, only the private key decrypts (RSA-OAEP). Signing: the private key signs, anyone verifies with the public key (RSA-PSS or PKCS#1 v1.5). Signing does not hide the message, and encryption does not prove who sent it.

RSA can only handle small payloads — typically you encrypt a symmetric key, not the data itself. Keys are exported as PEM: SPKI for public keys and PKCS#8 for private keys.

Processed locally in your browser — your input is never uploaded.

What is RSA & PEM Tools?

Generate keys, encrypt, decrypt, sign, verify. RSA uses a key pair. The public key can be shared; the private key must stay secret.

Is RSA & PEM Tools free to use?

Yes. RSA & PEM Tools on DevCipher is completely free, with no sign-up, no limits and no ads.

Is my data safe when I use RSA & PEM Tools?

Yes. Everything runs locally in your browser. Your input is never uploaded to a server, and sensitive values such as keys and tokens are never saved.

All developer tools

URL Encode / Decode — Encode and decode URLs side by side
Base64 Encode / Decode — Encode and decode Base64 side by side
Base64 Encoder — Encode text or files to Base64
Base64 Decoder — Decode Base64 back to text
Base64URL Encoder — URL-safe Base64 without padding
Base64URL Decoder — Decode URL-safe Base64
URL Encoder — Percent-encode text for URLs
URL Decoder — Decode percent-encoded text
Hex Encoder — Convert text to hexadecimal bytes
Hex Decoder — Convert hexadecimal bytes to text
Binary Encoder — Convert text to 8-bit binary
Binary Decoder — Convert 8-bit binary to text
Unicode Encoder — Escape characters as \uXXXX
Unicode Decoder — Turn \uXXXX escapes into text
HTML Entity Encoder — Escape &, <, >, quotes for HTML
HTML Entity Decoder — Turn entities back into characters
Image to Base64 — Convert an image to a Base64 data URI
Base64 to Image — Decode Base64 to an image and download it
AES Encrypt / Decrypt — AES-128/192/256 encryption and decryption
RSA & PEM Tools — Generate keys, encrypt, decrypt, sign, verify
Hash Generator — MD5, SHA-1/2/3, SHAKE and BLAKE2
HMAC Generator — Keyed hashes: HMAC-SHA256 and more
String ⇄ JSON — Convert escaped strings to JSON and back
JSON Formatter — Format, validate and minify JSON
JSON Comparator — Find differences between two JSON documents
JSON Tree Viewer — Explore JSON as an expandable tree
JSON to Code — Generate types for TypeScript, Java, Go, Python, C#
JWT Decoder — Decode and inspect JSON Web Tokens
JWT Generator — Create signed HS, RS and ES tokens
URL Parser — Break a URL into its components
Query String Parser — Parse and build query strings
UUID Generator — Generate UUID v4 and v7
Password Generator — Strong random passwords
Random String Generator — Secure random strings and tokens
Timestamp Converter — Unix timestamps ⇄ human dates
Number Base Converter — Binary, octal, decimal, hex and more
Color Converter — HEX, RGB and HSL with contrast check
Regex Tester — Test JavaScript regular expressions
CSV ⇄ JSON — Convert between CSV and JSON
YAML Formatter — Format, validate and convert YAML
XML Formatter — Pretty print, minify and validate XML
SQL Formatter — Format SQL for many dialects