Encrypt Text Online Free — AES-256 in Your Browser
Free online text encryption: AES-256-GCM with PBKDF2 key derivation, computed entirely in your browser. Your text and passphrase never leave your device.
About Text Encryptor / Decryptor
Turn any text into an encrypted string that only the passphrase can unlock — or reverse one. Encryption uses AES-256-GCM with a key derived from your passphrase via 600,000 rounds of PBKDF2, computed entirely in your browser with the Web Crypto API. Your text and passphrase are never sent anywhere.
How to use Text Encryptor / Decryptor
- Paste the text you want to encrypt (or an encrypted string to decrypt).
- Choose a strong passphrase.
- Click Encrypt (or Decrypt) and copy the result.
How this encryption works
The scheme
Your passphrase is stretched into a 256-bit key with PBKDF2-SHA256 (600,000 iterations and a random 16-byte salt), and the text is encrypted with AES-256-GCM using a random 12-byte IV. GCM is authenticated encryption: if anyone tampers with the ciphertext, decryption fails loudly instead of returning garbage.
The output is a single portable string — magic prefix, salt, IV, and ciphertext, base64-encoded — that you can store or send through any channel and decrypt with the same passphrase.
Choosing a passphrase
The encryption is only as strong as the passphrase. Use something long (a sentence of several words beats a short complex password), and never send it through the same channel as the encrypted text — share it separately, e.g. by phone or a different messenger.
If you lose the passphrase, the text cannot be recovered. There is no backdoor by design.
Why encrypt in the browser?
Most online encryption tools POST your text to a server — which defeats the purpose of encrypting it. Here, everything happens in the Web Crypto API on your device; you can even disconnect from the internet after the page loads and it keeps working.
Frequently asked questions
Is this tool really free?
Yes — free with no account and no limits.
Is my text uploaded anywhere?
No. Encryption happens in your browser via the Web Crypto API. The page works even offline once loaded.
Can I decrypt the result elsewhere?
The output uses a standard construction (PBKDF2 → AES-256-GCM, salt and IV included in the string), so any compatible implementation can decrypt it. This tool can decrypt anything it produced itself.
I forgot the passphrase — can you recover my text?
No, and nobody can. That is the point of real encryption: without the passphrase, the data is unrecoverable.
Which browsers are supported?
Any modern browser: Chrome, Firefox, Safari, and Edge.
Related tools
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to text, instantly in your browser.
WebAssemblyCLI / agentCase Converter
Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, and kebab-case.
WebAssemblyCLI / agentColor Converter
Convert colors between HEX, RGB, and HSL formats instantly.
WebAssemblyCLI / agentCSS Formatter
Beautify (pretty-print) minified or messy CSS instantly, right in your browser.
runs locallyCSV to JSON Converter
Convert CSV data to a JSON array of objects, using the header row as keys.
WebAssemblyCLI / agentHash Generator
Calculate MD5, SHA-1, SHA-256, SHA-512, and CRC32 checksums of any text.
WebAssemblyCLI / agent