Handling UTF-8 & Unicode in Base64: Avoiding Character Corruption
How to properly encode Arabic, Chinese, Urdu, Hindi, Cyrillic, and emojis in Base64 without Mojibake or decoding errors.
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A frequent bug in legacy JavaScript applications occurs when converting text with non-ASCII characters (such as Arabic, Urdu, Japanese, or emoji like 🚀) into Base64 using naive `btoa()` calls.
Why Naive btoa() Fails
JavaScript strings are stored internally as UTF-16 code units. The browser `btoa()` function expects each character code to fit within a single 8-bit byte (0x00 to 0xFF). When encountering a character like `🚀` (code point U+1F680), `btoa()` immediately throws an uncaught error.
The Correct Modern Solution: TextEncoder & TextDecoder
The modern W3C standard approach converts the JavaScript string into a strict UTF-8 `Uint8Array` first: ```javascript // Safe Encoding const utf8Bytes = new TextEncoder().encode("Hello 🌍 مرحبا"); const base64 = btoa(String.fromCharCode(...utf8Bytes)); // Safe Decoding const rawBytes = Uint8Array.from(atob(base64), c => c.charCodeAt(0)); const originalString = new TextDecoder().decode(rawBytes); ```
Toolstack's Base64 tools implement this standard natively, guaranteeing 100% accurate translation across all global languages.
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