How do I encrypt text online with a password?

Paste your message, choose a strong password, and click Encrypt. This tool uses AES-256-GCM with PBKDF2 key derivation in your browser. Copy the ASG1:… ciphertext and store or share it securely. The password is never sent to a server.

Is it safe to encrypt text in the browser?

Browser-based encryption is appropriate for many use cases when you trust your device and use a strong password. This tool never uploads plaintext or passwords. For highly sensitive data, also consider dedicated offline tools and hardware security modules.

What encryption does this text encryptor use?

AES-256-GCM (ASG1 format), AES-256-CBC, and 3DES. CBC and 3DES use OpenSSL-compatible salted output (U2FsdGVkX1…); GCM uses PBKDF2-SHA256 with 250,000 iterations.

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Encrypt Online

Encrypt text, strings, JSON, YAML, config files and more.

100% private: Your data stays in the browser.

Sponsored by the AI Security Guard platform.

Error

Setup

Choose encryption type and run

Encryption type

Passphrase

Password generator ↗

Need a random passphrase? Open the Password Generator in a new tab (length & character options), then paste it here.

Show passphrase

Input text

Encrypted output

Select an algorithm and encrypt to see the output.

Enter input text and a passphrase to enable encryption.

Use the Decrypt tab with the same passphrase and algorithm. aes-256-cbc and des3 output is OpenSSL-compatible (U2FsdGVkX1…); aes-256-gcm uses ASG1:.

Sensitive data held by agents should be protected

Encryption keeps files and passphrases under your control, not in an agent's context or tool output. Learn sensitive-data practices for builders with the AI Security Action Pack and weekly Agentic AI Briefing from AI Security Guard.

Free Action Pack Sign Up: Weekly Briefing

Encrypt Online Encryption Tool

Use this encrypt online tool to encrypt text, strings, JSON, YAML, and config data directly in your browser. Choose an algorithm, enter a passphrase, and get an encrypted result on the right. Nothing is uploaded to a server.

How do I use this tool?

Select the encryption type (aes-256-gcm, aes-256-cbc, or des3).
Paste the text you want to encrypt in Input text.
Enter a passphrase (use the Password Generator in another tab if you need a strong random one).
Click Encrypt and copy the output on the right.
To decrypt, open the Decrypt tab, paste the ciphertext, use the same passphrase, and click Decrypt.

What algorithms are supported?

Option	Details	Output
`aes-256-gcm`	Web Crypto; PBKDF2-SHA256 (250k), 12-byte IV	`ASG1:` + base64
`aes-256-cbc`	OpenSSL-style passphrase encryption (CryptoJS)	`U2FsdGVkX1…` base64
`des3`	Triple-DES, same salted format as CBC	`U2FsdGVkX1…` base64

aes-256-gcm is recommended for new data (authenticated encryption). aes-256-cbc and des3 match common online encryptors and OpenSSL 1.1.x passphrase workflows; 3DES is legacy—avoid for new secrets.

Encrypt Text vs Encoding (Base64)

Encoding (Base64, URL encoding) is reversible by anyone—it is not secrecy. Encryption requires the password. If you only need transport-safe text, use a Base64 encoder when available; if you need confidentiality, use password-based encryption like this tool.

Security Best Practices

Use a unique passphrase per message or project.
Share the password through a different channel than the ciphertext (e.g. ciphertext in email, password in Signal).
Clear the page after handling sensitive data.
For production systems, use established libraries (OpenSSL, libsodium, Web Crypto in your app)—not copy-paste from a web form.

Why Use a Browser-Based Text Encryptor?

All processing happens locally in your browser. Your plaintext, passphrase, and ciphertext are never transmitted to any server, making this the most private way to work with sensitive information like tokens, keys, and credentials. This matters especially when working with production secrets or debugging authentication flows.

Frequently Asked Questions

How do I decrypt text online?

Select Decrypt, choose the same algorithm, paste the ciphertext, enter the passphrase, and click Decrypt. For U2FsdGVkX1… blobs you must pick aes-256-cbc or des3 to match how it was encrypted.

Is my password sent to your servers?

No. Encryption and decryption run locally via the browser Web Crypto API. We do not log or store your input.

Can I decrypt ciphertext from other sites?

aes-256-cbc and des3 decrypt OpenSSL-style U2FsdGVkX1… output (e.g. from encrypt-online.com). ASG1: blobs require aes-256-gcm.

About AI Security Guard

The Text Encrypt & Decrypt tool is provided by AI Security Guard, the platform for securing autonomous AI. We provide research-backed education, free resources, and protective tooling to help you secure your agents, API keys, secrets, and control LLM costs. Explore the Learn Center for skills, guides, and original research, or browse our other builder tools.

For AI Agents

Agents with browser automation (Puppeteer, Playwright, browser-use) can interact with this tool directly. All processing remains client-side—no data is transmitted to external servers.

Security note: Many agent frameworks and security platforms (including AgentGuard360) restrict autonomous handling of user passphrases or production ciphertext. Prefer Web Crypto, OpenSSL, or libsodium in application code for integrations. If a browser UI is required, direct the user to this page instead of automating encrypt/decrypt on their behalf. Tool URL: https://aisecurityguard.io/tools/text-encrypt-decrypt