File & Text Encryptor
Zero Server Upload · 100% Local EncryptionSecurely encrypt and decrypt files and text in your browser. Industry-standard AES-256-GCM and PBKDF2 without sending passwords or files to any external server.
Drop files here to encrypt or decrypt
or click to select from your device (multiple files supported)
Key features of File & Text Encryptor
- Industry-standard AES-256-GCM authenticated encryption with PBKDF2-HMAC-SHA-256 key derivation
- Zero server uploads: all cryptographic computation executes strictly inside your browser
- Tamper-evident 128-bit GCM authentication tag and SHA-256 original byte integrity verification
- Supports batch encryption for multiple files with per-file salts/IVs and instant ZIP download
About File & Text Encryptor
Solasu's File & Text Encryptor is a private, client-side security tool designed to protect your sensitive documents and communications without external server dependencies.
Utilizing the National Institute of Standards and Technology (NIST) recommended AES-256-GCM authenticated cipher and robust PBKDF2-HMAC-SHA-256 key derivation, this tool allows you to encrypt arbitrary files—such as PDFs, photos, office documents, and archives—as well as plain text.
All computations execute locally inside your browser's Web Crypto API and background Web Workers. Passwords, encryption keys, and plaintext data never touch external servers or local persistent storage.
Authenticated Encryption with AES-256-GCM and Tamper Resistance
This tool employs Galois/Counter Mode (AES-256-GCM), the gold standard in symmetric encryption. AES-GCM guarantees both confidentiality (data privacy) and authenticity (tamper detection via a 128-bit authentication tag).
If an attacker alters even a single bit of the ciphertext or container headers, decryption halts immediately with an authentication error. No partial or corrupted plaintext is ever displayed.
Robust Key Derivation (PBKDF2) with Independent Salts and IVs
User passwords are never directly used as raw encryption keys. A unique 16-byte cryptographically secure random salt is generated for every encryption operation, deriving a high-entropy 256-bit AES key via PBKDF2-HMAC-SHA-256.
A fresh 96-bit random Initialization Vector (IV / Nonce) is generated per file. Even encrypting the exact same document twice with the exact same password yields completely distinct ciphertexts, thwarting pattern recognition and dictionary attacks.
Self-Contained Binary Container (.enc) and Text Format (SLTEXT1)
Encrypted files are packaged into a structured binary container (.enc) holding magic identification bytes (SLSEC), versioning, cryptographic parameters, authenticated metadata, ciphertext, and the GCM authentication tag.
For maximum privacy, original filenames are stored within the encrypted metadata, invisible without the password. In text mode, the container is encoded into a convenient versioned string format (SLTEXT1:...) ready for email or chat.
Zero Server Transmission and Memory Safety
All cryptographic routines run strictly on your device's CPU. External network calls during encryption and decryption are strictly zero. No data is stored in localStorage, IndexedDB, or cookies.
A safety guard of 250 MB prevents browser tab crashes from unbounded memory allocations. In-memory buffers are promptly released upon operation completion or reset.
Frequently Asked Questions
Can I encrypt any file format?
Yes. You can encrypt PDFs, photos (JPG, PNG), Word and Excel documents, ZIP archives, videos, or arbitrary binary data. The tool processes raw bytes without restrictions.
Can I encrypt plain text?
Yes. Switch to the 'Text' mode tab to encrypt confidential notes, passwords, or secret messages. The output is provided in an easy-to-copy SLTEXT1 format.
What is AES-256-GCM?
AES-256-GCM (Galois/Counter Mode) is an internationally recognized symmetric authenticated cipher that provides both strong confidentiality (256-bit key) and built-in tamper detection (128-bit authentication tag).
Are files uploaded to a server?
No. All encryption and decryption operations execute entirely inside your web browser. Zero bytes of your files or passwords ever leave your machine.
Is my password sent to Solasu or any third party?
No. Your password is used only within your browser's native Web Crypto API. It is never transmitted over the network or logged.
Can I decrypt the file on another computer or smartphone?
Yes. As long as you open the Solasu File & Text Encryptor and provide the correct password, you can decrypt your .enc file on any device, operating system, or modern browser.
What happens if I forget my password?
If you lose your password, your data cannot be recovered. Solasu does not store passwords and has no backdoors or recovery mechanisms. Always keep your password safe.
What format are encrypted files saved in?
Encrypted files are saved with the extension .enc. They are self-contained binary containers containing the necessary salt, IV, iteration count, and ciphertext.
Is the original filename preserved?
By default, the original filename is stored inside the encrypted metadata so it can be restored upon decryption. An attacker without the password cannot read it. You can also choose to hide it completely in settings.
Can I encrypt multiple files at once?
Yes. You can drop multiple files to encrypt them in batch. Each file receives its own independent salt and IV. Once complete, you can download them individually or as a single ZIP archive.
Can I encrypt large files?
Files up to 100 MB work smoothly on most devices. To prevent browser memory exhaustion and tab crashes, a hard safety limit of 250 MB is enforced.
What happens if an incorrect password is entered?
The AES-GCM 128-bit authentication tag verification will fail, and a clean error stating that the password is incorrect or the data is corrupted will be displayed. Decryption is aborted.
What happens if the encrypted file is tampered with?
AES-GCM verifies that every single byte of the header and ciphertext matches the cryptographic tag. Any modification causes authentication failure, preventing corrupted data from being exposed.
What is PBKDF2?
PBKDF2 (Password-Based Key Derivation Function 2) is a standard algorithm that stretches passwords into cryptographic keys using hundreds of thousands of hashing rounds, making brute-force attacks difficult.
What is a Salt?
A salt is a random 16-byte value mixed with the password during key derivation. It ensures that identical passwords produce completely different encryption keys.
What is an IV (Initialization Vector)?
An IV is a single-use 96-bit random nonce used alongside the encryption key in AES-GCM. Solasu generates a new cryptographically secure random IV for every single operation.
What is the AES-GCM authentication tag?
The authentication tag is a 128-bit checksum computed during encryption that mathematically verifies data authenticity and integrity upon decryption.
Is any data stored on Solasu servers?
No. Solasu has no database, user accounts, or server storage. All states are kept in temporary browser memory and cleared when the tab is closed.
Does data persist in localStorage or IndexedDB?
No. Neither passwords, plaintexts, ciphertexts, nor encryption keys are ever saved to browser persistent storage.
Does it work on mobile browsers?
Yes. Modern mobile browsers like iOS Safari and Android Chrome fully support the Web Crypto API, enabling seamless mobile encryption and decryption.
Is SHA-256 encryption?
No. SHA-256 is a one-way cryptographic hash function used for verifying that decrypted bytes match the original input. The reversible encryption is handled by AES-256-GCM.
Can Solasu recover my forgotten password?
No. Solasu has zero knowledge of your passwords or files and cannot recover or reset forgotten credentials.