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Encrypt or decrypt data online using the Blowfish symmetric algorithm to ensure privacy and security. Supports multiple encoding formats including UTF-8, Base64, and Hex.
Please enter content and click Encrypt/Decrypt.
Overview
Understand what the tool solves, how it works, and the boundaries of its data.
Blowfish is a symmetric block cipher: encryption and decryption use the same key, and the block size is 64 bits. Use this page to reproduce a known older configuration or inspect a harmless test, rather than as a new protection design. The encryption input is text. For decryption, paste ciphertext as Base64 or hexadecimal (Hex); output includes Base64 and Hex, and readable text for decryption.
Successful recovery depends on matching key bytes and key format, key size, mode, padding, IV, and ciphertext encoding. A text key is measured in UTF-8 bytes; Hex and Base64 are decoded before length checking. Base64 and Hex encode bytes for display and copying; neither is encryption.
| Setting | Choices | Check |
|---|---|---|
| Key length | 128, 192, 256, 448 bits; default 256 | Decoded key byte length must match. |
| Mode | ECB, CBC, CFB, OFB; default CBC | Use the same mode to decrypt. |
| Padding | PKCS7, Zero, None, ISO 10126, ANSI X.923 | Use identical padding. |
| IV | Hex or Base64 where required | CBC, CFB, OFB need it; ECB does not. |
A Blowfish IV is 8 bytes. Automatic generation shows an IV separately, and ciphertext does not package it. Keep the IV and all settings with test ciphertext for a future decode.
Guide
Follow the workflow and verify inputs and outputs with practical examples.
Use CBC and PKCS7 defaults unless a documented legacy system requires something else. Select a key size and representation compatible with that system.
Use a harmless phrase and test key. A generated key is Hex, so leave its format set to Hex.
CBC, CFB, and OFB require an IV. Save the shown value separately after encryption because it is not included in the ciphertext output.
Paste the full Base64 or Hex ciphertext and restore the same key, mode, padding, and IV. Compare bytes as well as readable text.
If Hex output appears but text is blank or garbled, it may not be valid UTF-8, or one of the parameters may be wrong. Confirm the source text encoding and compare the bytes with the other system before deciding whether decryption succeeded.
Use cases
See how the tool fits into real work and everyday tasks.
Use documented parameters and non-secret data to isolate a mismatch in key bytes, mode, padding, or IV.
Hold a test message constant and change the mode or IV to observe compatibility effects, not production security.
Record harmless input, complete settings, and expected output as a regression case while replacing an older component.
Q&A
Find concise answers to common questions and confusing cases.
The selected length is in bytes after decoding the chosen format. A Unicode text key can occupy more UTF-8 bytes than characters; Hex uses two digits per byte.
The output does not bundle the IV. Save it alongside the ciphertext and restore it for decryption.
Hex shows bytes even when they are not valid UTF-8. Check source encoding, key format, mode, padding, and IV.
Notes
Review scope, result limitations, and important precautions before use.
The available ECB, CBC, CFB, and OFB modes do not authenticate a message; output does not prove ciphertext was unmodified. Blowfish’s 64-bit block size has documented collision limitations at high data volumes. Keep passwords, private keys, tokens, personal data, and production secrets out of this page. Choose a security-reviewed modern authenticated-encryption design for new systems.
Related
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