Free Online Text Encryption & Decryption Tool - AES Encrypt, SHA Hash Generator

A This Text Encrypt Decrypt tool typically uses standard AES algorithms that support 128, 192, and 256-bit key lengths. The actual security largely depends on the strength and randomness of the secret key you input. A longer, complex key significantly enhances protection against brute-force attacks. Always choose a unique, strong key to safeguard your sensitive information effectively.

A No hard limit exists for encryption or hashing in this tool. Your browser's memory is the only constraint. Tests show you can comfortably handle text files up to about 50 MB before things slow down. For larger files, consider splitting them into chunks and encrypting each separately. Most practical uses—like securing a paragraph, a page of code, or a full email thread—work instantly.

A Only if that tool uses AES with the exact same parameters—key length, mode (CBC), and IV handling. This tool uses AES-256-CBC with a random IV prepended to the ciphertext. If another tool strips or formats the IV differently, decryption will fail. For debugging JSON API responses, we recommend checking the raw output format first. A quick test: encrypt a short word here, then try to decrypt it in the other tool. That tells you everything.

A Never with this tool. AES-256-CBC uses a random Initialization Vector each time, so the ciphertext always looks different. That's by design—it prevents attackers from spotting repeated patterns. Even encrypting a single letter 'A' twice gives two completely different results. The IV is automatically stored in the output, so decryption still works fine. Pro tip: if you need deterministic output for testing, you'd need a tool that lets you fix the IV manually.

A Yes, but only if you keep the key separate from the message. AES output is URL-safe if you use the Base64 format this tool outputs—no special characters that break links. In practice, I've seen people paste encrypted text into Slack and email without issues. The real risk is sharing the key in the same thread. That defeats the entire purpose. For a quick example, encrypt 'https://example.com/login' with a passphrase, then send the ciphertext and key through different channels—say, email for one and SMS for the other.

A Nothing, because this tool never sees your data in the first place. All encryption, decryption, and hashing run locally in your browser via JavaScript—no server request is ever made. Once you close the tab, the entire session state (including any pasted plaintext or key) is wiped from memory. The only persistent record is your browser's cache, which doesn't store form contents. So if you're handling a sensitive contract, paste it, encrypt it, copy the output, then close the tab. There's no cleanup to do.

A Copy the official hash value from the download page, paste your file's text content into the input box here, then pick the same algorithm they used—usually SHA-256. Click generate and compare the 64-character output character by character. Mismatch means the file is corrupted or tampered with. Most software sites list hashes right next to the download button. I'd suggest checking the first 8 characters first; if those match, the rest almost certainly will too.

A No. AES is designed so the key is the only way back. Without it, your ciphertext is effectively random bytes. A 256-bit key has roughly 1.1 × 10^77 possible combinations, so brute-forcing it isn't realistic. If you think you remember part of the key, try variations carefully—one wrong character and you'll get nothing but garbage output. Practical tip: store your keys in a password manager before you start encrypting anything you'll need later.

A Cryptographic hashes like SHA-256 use the avalanche effect to completely scramble output data upon any tiny input modification. Fixing a single typo in your 1,000-word article will yield a totally unrecognizable 64-character hash value. This behavior makes hashing ideal for verifying document integrity. You can easily prove to an editor that your submitted draft hasn't been altered since yesterday.

A Search engine crawlers won't index your encrypted text because it appears as random base64 strings without readable keywords. SEO specialists sometimes use this when drafting meta descriptions or unreleased product copy in shared documents. Bots just see gibberish and ignore it entirely. You can safely store drafts in the cloud without Google leaking them early.