Text Decryptor
Decrypt ciphertext back into readable plain text with this free online tool. It is perfect for developers, security testers, and users retrieving secured messages. Use it to decode encrypted data when you have the correct secret key.
How the Text Decryptor works
- 1
Paste the blob and the password
The encrypted message is one Base64 blob — the random salt and IV that were generated at encryption time travel inside it. Paste that into the input, then type the same password the sender used.
- 2
Key derivation and AES-GCM
Your password and the embedded salt produce a decryption key through a key-derivation function, then the browser's Web Crypto engine runs AES-GCM over the ciphertext. Nothing is selected by hand — the format carries its own parameters.
- 3
Read or diagnose
A correct pairing returns the original plain text. A wrong password or tampered blob fails loudly with an error rather than producing scrambled nonsense, which is the authentication doing its job.
Real-world examples
Recovering a Shared Note
Input: A Base64 blob from the Text Encryptor plus the agreed password
Results: The original message, character for character
Use case: Colleagues reopen encrypted reminders weeks later without keeping plaintext copies around.
Wrong Password Diagnosis
Input: A valid blob with a mistyped password
Results: A decryption failure, never scrambled half-text
Use case: Users learn immediately that the password — not the blob — is the problem.
Corrupted Input Check
Input: Text that is not valid Base64
Results: An immediate "not valid Base64" error before any crypto runs
Use case: Developers spot copy-paste truncation at a glance instead of debugging silent failures.
Cross-Device Handoff
Input: The same blob and password on a different laptop
Results: Identical decrypted text — nothing about the first device is baked in
Use case: Travellers decrypt trip details from any machine once they arrive.
Truncated Blob Detection
Input: A blob cut short by an over-eager chat client
Results: A "too short" error, since the header cannot possibly fit
Use case: Recipients notice instantly when messaging software mangled their payload.
Text Decryptor FAQ
Do I need to create an account?
No, you can use this tool immediately without signing up or logging in.
Is my data secure and private?
Yes, all processing happens directly in your browser, so no data is ever sent to our servers.
Does it work offline?
Once the page is loaded, the core logic works offline since it runs locally in your browser.
Is there a character or size limit?
There is no strict limit, but extremely large inputs may depend on your browser processing capabilities.
Does it support multiple languages?
The interface is in English, but it fully supports standard characters and inputs from all global keyboard layouts.
How is it different from similar tools?
The decryption runs entirely in your browser as local JavaScript — there is no account step and nothing is uploaded, and the blob format carries its own salt and IV so no settings need configuring.
What is the technical working principle?
The Base64 blob decodes to a 16-byte salt, a 12-byte IV, and the ciphertext. Your password plus that salt derive the AES key, and the browser's Web Crypto API runs authenticated AES-GCM decryption with the embedded IV.
What happens if the password is wrong?
AES-GCM carries an authentication tag, so a wrong password fails the check and surfaces as an error — you never receive convincing-looking garbage that is quietly wrong.
What is a common use case?
Users use it daily to decrypt sensitive text messages or files received from colleagues over secure channels.
Why use the Text Decryptor?
- Instant Processing: Get immediate results without waiting for server responses or page reloads.
- Zero Registration: Start working right away without the hassle of creating an account.
- Complete Privacy: Your inputs are processed on your device and are not uploaded anywhere.
- User-Friendly Interface: Enjoy a clean, distraction-free layout designed for quick and easy use.
- Cross-Platform Compatibility: Works seamlessly on desktops, tablets, and mobile web browsers.
- No Software Installation: Access the tool directly from your browser without downloading anything.
- Real-Time Updates: See the output update automatically as you paste or modify the ciphertext and key.
- Completely Free: Access all features without any hidden fees, subscriptions, or premium upgrades.
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