100% Client-Side
Your code is processed locally in your browser. No server upload is required, and there are no analytics or external code-processing APIs.
Decode Base64 HTML Instantly
Paste Base64-encoded markup and turn it back into normal, readable HTML. Full UTF-8 support, a lightweight formatter, and a sandboxed preview — everything runs locally in your browser. Base64 is an encoding format, not encryption.
Your code stays in your browser. Nothing is uploaded.
Base64 Input
0 characters · 0 tokens
Tip: drop a .txt, .html or .base64 file here
Decoded HTML
Decoded HTML will appear here.
0 characters · 0 lines
HTML Preview
The preview renders inside a sandboxed iframe that is isolated from this page. Decoded HTML is untrusted: it can contain scripts, trackers or requests to external resources. Only preview code you understand.
Full UTF-8 Support
Decoding uses TextDecoder, so English, Urdu, Arabic, Hindi, emoji and every other Unicode character survive the round trip intact.
Isolated Preview
Decoded markup is never injected into this page's DOM. Previews run in a sandboxed iframe that cannot reach the parent application.
About the ZHH Base64 HTML Decoder
ZHH Base64 HTML Decoder is a free online Base64 decoder and HTML deobfuscator for developers. Paste an encoded string, decode Base64 HTML back to source, then format, minify, preview, copy or download it. It also encodes HTML back to Base64 with correct UTF-8 handling.
Base64 is encoding, not encryption
Anyone can decode Base64 — it provides no confidentiality or security whatsoever. It exists to represent binary or text data safely in text-only contexts, not to protect it.
About the formatter
The built-in formatter applies straightforward indentation rules and leaves script, style, pre and textarea blocks untouched. It is a readability helper, not a full production-grade HTML parser, so unusual or malformed markup may not be reflowed perfectly.