Encoder/Decoder
Encode and decode Base64 strings, files, and URL percent-encoded query parameters with Unicode support.
How to Use Encoder/Decoder
Select Mode
Choose between Text mode or File/Image mode.
Enter Text or Upload File
Type or paste text, or drag & drop an image/file to convert.
Encode or Decode
Toggle URL-Safe format, copy the result or download the decoded file.
Key Benefits
- Full Unicode UTF-8 support: No corrupted characters or broken accented text
- URL-Safe Base64 mode replacing + and / with - and _
- Direct image and file encoding with instant preview and download
- 100% private in-browser conversion
Browser & Hardware Notes
- Very large files (>50MB) may take a few moments to encode into Base64 strings.
Frequently Asked Questions about Encoder/Decoder
How Encoder/Decoder Operates Privately on Your Device
Unlike traditional cloud services that transmit your confidential files across the open internet to remote servers, SafeWebUtil operates on a strict zero-upload client-side architecture. Every transformation performed by Encoder/Decoder executes exclusively within your browser's secure memory sandbox.
Native Web Crypto API (SubtleCrypto)
All cryptographic hashing, signing, and encryption routines strictly execute through browser-native Constant-Time primitives, immune to timing side-channel attacks.
Authenticated Military-Grade Ciphers
Utilizes AES-256-GCM authenticated encryption and PBKDF2 with high iteration counts to ensure data confidentiality and cryptographic tamper resistance.
Zero Ingestion & Ephemeral Memory
Plaintext passwords, JWT tokens, and symmetric keys reside exclusively in temporary JavaScript memory and are zeroized as soon as the tab is closed.
Engineering Insights & Performance Best Practices for Encoder/Decoder
Cryptographic algorithms execute via constant-time Web Crypto primitives. Confidential JWT tokens, private passwords, and symmetric encryption keys never leave your machine.
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