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Convert text strings, images, and binary files to standard Base64, URL-safe Base64, or Data URIs instantly in your browser. Zero network uploads ensure complete data privacy.
Toggle between Encode and Decode. Choose either raw text string input or drag-and-drop file/image upload.
Optionally enable URL-Safe Base64 (RFC 4648 §5) or format output as an HTML/CSS Data URI. Output updates live as you type or drop files.
Click Copy to transfer Base64 strings to your clipboard, or click Download to save decoded binary files directly to disk.
All encoding and decoding operations execute inside browser memory using Web APIs (TextEncoder, FileReader, atob, btoa). Zero network requests.
Switch seamlessly between text strings and binary/image file uploads to generate raw Base64 strings or Data URIs.
Toggle URL-safe mode ('-' and '_' replacing '+' and '/') to format strings safely for query parameters and JWT tokens.
Automatically formats image Base64 output as HTML/CSS Data URIs (`data:image/png;base64,...`) with live inline visual previews.
Decode binary Base64 strings back into original downloadable files (images, PDFs, documents) with auto-detected file extensions.
Live byte count comparison showing original size vs encoded size (+33% overhead calculation) for performance auditing.
Our Base64 engine is fully open-source under HiMat Technology. Star the project, inspect the encoding implementation, or submit contributions on GitHub.
Unlike traditional online converters that upload user strings or images to remote servers, HiMat's Base64 tool executes entirely inside your browser using native JavaScript TextEncoder, FileReader, and Web Crypto standards. Secret keys, credentials, and confidential documents never leave your local machine.
No. The HiMat Base64 Encoder & Decoder operates 100% locally inside your web browser. Neither text strings nor uploaded file payloads are ever transmitted across the network.
Standard RFC 4648 Base64 uses standard characters '+' and '/' with '=' padding. URL-Safe Base64 replaces '+' with '-' and '/' with '_', avoiding percentage-encoding issues in URL query strings and JWT tokens.
Yes! You can drop any image or binary file up to tens of megabytes to instantly convert it to a Base64 string or an HTML Data URI suitable for inline CSS or web applications.
Yes, 100% free with no registration, no daily usage caps, and zero advertisements.
HiMat Technologies designs and builds scalable web platforms, custom developer tooling, agentic AI engines, and modern SaaS products for tech founders and modern enterprises.