Text Encrypt & Decrypt
Securely encrypt and decrypt text using AES-256-GCM encryption with a password. All processing happens locally in your browser.
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Introduction
Passing sensitive information through email, chat, or shared documents in plaintext is a security risk that most people underestimate—intermediary services, IT administrators, and compromised accounts can all read unencrypted messages. A text encrypt/decrypt tool applies symmetric-key encryption to your plaintext, producing a ciphertext string that is unreadable without the passphrase you choose. The same tool, with the same passphrase, reverses the process to recover the original text, providing a simple but effective layer of confidentiality for messages, credentials, and notes stored or transmitted in insecure environments.
What Is Text Encrypt/Decrypt?
A text encrypt/decrypt tool is a client-side cryptographic utility that applies symmetric-key encryption to convert plaintext into an unreadable ciphertext and vice versa. This implementation uses the AES-GCM (Advanced Encryption Standard in Galois/Counter Mode) algorithm, which provides both confidentiality (the data cannot be read without the key) and authenticity (any tampering with the ciphertext is detected during decryption). The passphrase is strengthened using PBKDF2 key derivation with 100,000 iterations and a random salt, which makes brute-force attacks on weak passphrases computationally expensive.
The tool exists because many everyday communication channels—email, Slack, SMS—lack end-to-end encryption for message content, and the sensitive data we share through them (passwords, API keys, personal identification numbers) is often the most valuable to attackers. Rather than relying on the security of the transport layer, this tool encrypts the content itself, so even if the message is intercepted or stored on a compromised server, the plaintext remains inaccessible without the passphrase.
Running the encryption entirely in the browser via the Web Crypto API is a critical security feature. The plaintext, the passphrase, and the derived key exist only in volatile memory and are never transmitted to any server. When you close the tab, all cryptographic material is garbage-collected and unrecoverable. This local-only architecture eliminates the risk of server-side key leakage that plagues cloud-based encryption services.
Text Encrypt/Decrypt Examples
| Input | Output |
|---|---|
| Encrypt: 'Database password: xK9#mP2v' with passphrase 'my-secret-key' | U2FsdGVkX1+3aB7kRmNpQsT8vWxYzA0bC2dE4fG6hI== (Base64-encoded AES-GCM ciphertext; actual output varies due to random IV and salt) |
| Decrypt: 'U2FsdGVkX1+3aB7kRmNpQsT8vWxYzA0bC2dE4fG6hI==' with passphrase 'my-secret-key' | Database password: xK9#mP2v |
| Decrypt with wrong passphrase: 'U2FsdGVkX1+3aB7kRmNpQsT8vWxYzA0bC2dE4fG6hI==' with passphrase 'wrong-key' | Error: Decryption failed — invalid passphrase or corrupted ciphertext |
| Encrypt: 'Launch code: ALPHA-7429' with passphrase 'mission-control-2024' | A different Base64 string than example 1 due to unique IV and salt per encryption operation, even with different plaintext |
Key Features of Text Encrypt/Decrypt
- AES-256-GCM encryption providing both confidentiality and authenticated encryption (tamper detection)
- PBKDF2 key derivation with 100,000 iterations and a random 128-bit salt to resist brute-force attacks on the passphrase
- Random 96-bit initialization vector (IV) per encryption operation ensuring identical plaintexts produce different ciphertexts
- Base64-encoded output that is safe for transmission through email, chat, and text-storage systems
- Client-side processing via the Web Crypto API—plaintext and passphrase never leave the browser
- Passphrase strength indicator that warns when a passphrase is shorter than 12 characters or lacks complexity
- Integrity verification that detects and rejects corrupted or tampered ciphertext during decryption
How It Works
Enter Your Plaintext and Passphrase
Type or paste the text you want to encrypt into the input field, then choose a strong passphrase. The same passphrase will be required later to decrypt the ciphertext back into readable form, so store it somewhere safe before proceeding.
AES-256 Encryption Processes Your Text
The tool applies the AES-256 symmetric encryption algorithm using your passphrase to generate a cryptographic key. Your plaintext is transformed into an unreadable ciphertext string that cannot be reversed without the exact same passphrase, ensuring your sensitive data stays protected.
Decrypt with the Same Passphrase
To recover the original text, paste the encrypted ciphertext into the input area and enter the same passphrase used during encryption. The tool reverses the AES-256 process, verifying the passphrase matches before returning your original plaintext exactly as it was entered.
Who Uses This
Privacy-Conscious Professionals
encrypting sensitive client details or internal memos before sharing them over email or messaging platforms that lack end-to-end encryption
Journalists and Sources
protecting the contents of confidential communications by encrypting messages with a shared passphrase that only the intended recipient knows
IT Administrators
securely storing configuration snippets, API keys, or credential hints in encrypted form within shared documentation systems without exposing plaintext secrets
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