Free Text Encrypt & Decrypt – AES-256 in Your Browser

Encrypt Text With a Password, Right in Your Browser

Text encryption converts a readable message into an unreadable string that can only be reversed by someone who knows the password. The specific algorithm here is AES-256-GCM, an authenticated cipher that both scrambles the content and detects tampering, backed by PBKDF2 key derivation so your password is never used raw as a cryptographic key. The output is a single base64 string containing everything the recipient needs — salt, initialization vector, and ciphertext — which you can paste into an email, a chat message, or a notes file. The recipient pastes that string back in, enters the same password, and gets the original text. No account, no server, no stored keys. Here is what happens under the hood when you click Encrypt. Your password is combined with a freshly generated random salt and run through PBKDF2-SHA256 for a high iteration count, producing a 256-bit key that is computationally expensive to guess. A random 12-byte initialization vector is generated next. The plaintext is then encrypted with AES-256 in GCM mode using that key and IV, which produces both ciphertext and a 128-bit authentication tag. The salt, IV, ciphertext, and tag are concatenated into a single byte array and encoded as base64 for safe text transport. Because the salt and IV are random every time, encrypting the same message twice yields completely different output, which prevents pattern analysis. Decryption reverses the process: it splits the base64 back into salt, IV, and ciphertext, re-derives the key from the password and salt, and decrypts. If the password is wrong or any byte was altered, GCM's authentication check fails and the tool reports an error rather than returning garbled text. A worked scenario. You need to send a Wi-Fi password — say BlueSky#2024! — to a colleague over Slack, which you consider insufficiently private. You type the password into the encrypt field, enter the shared passphrase you agreed on in person — OfficeQ3 — and click Encrypt. The tool outputs something like U2FsdGVkX1+... (a long base64 string). You paste that into Slack. Your colleague opens the decrypt tab, pastes the base64, types OfficeQ3, clicks Decrypt, and sees BlueSky#2024! in plain text. If an eavesdropper intercepts the base64 string without knowing the passphrase, they cannot recover the Wi-Fi password without brute-forcing PBKDF2, which is computationally prohibitive at the iteration count used. Real situations. A journalist encrypts source notes before storing them in a cloud drive that might be subpoenaed, keeping the passphrase memorized. A developer shares a production database credential with a teammate by encrypting it and sending the passphrase over a separate voice call. A student encrypts a personal diary entry before pasting it into a shared Google Doc that doubles as scratch space. A lawyer sends a settlement figure to opposing counsel encrypted, then texts the passphrase from a different number. A startup founder stores sensitive investor-term details in encrypted form inside a Notion page, decrypting only when needed. A traveller keeps passport and insurance numbers encrypted in a plain-text note on their phone so a pickpocket who unlocks the phone still cannot read the data without the passphrase. Two things you must understand clearly. First, there is no password recovery — if you forget the passphrase, the encrypted text is permanently unrecoverable by anyone, including the tool's developers, because no key escrow exists and no server ever sees your password. Treat the passphrase like a physical key to a safe. Second, the passphrase must be shared through a separate trusted channel: in person, over a phone call, or via a different messaging app — never in the same thread as the ciphertext, because anyone reading that thread then has both pieces. All cryptographic operations use the browser's built-in WebCrypto API; your plaintext and password never leave your device, and the tool functions fully offline once loaded.

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