Base64 Encoder & Decoder
Encode or decode text, emojis and Unicode using standard Base64 or URL-safe Base64. No upload, no sign-up.
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Free online toolReady. All conversions run in your browser.
What this tool does
Base64 is a reversible way to represent bytes using ASCII characters. It is useful for APIs, email payloads, data URLs and testing, but it is not encryption.
How to encode and decode Base64
- To encode text, paste a phrase (such as
Hello Vyblet!) and choose Encode text → Base64. You can copy the ASCII output into a test request. - To decode, paste a Base64 string such as
SGVsbG8=and choose Decode Base64 → text. The result isHello. - Use Base64URL if the result will be placed in a URL, a JWT component or another context that prefers hyphens and underscores over plus signs and slashes. The URL-safe format normally omits equals padding.
Unicode matters: Base64 encodes bytes, not characters
Browsers store text as Unicode. Vyblet first converts your text to UTF-8 bytes and only then applies Base64. This means strings with Chinese characters, accented letters and emoji round-trip correctly. Invalid UTF-8 in a decoded byte sequence produces a clear error rather than silently replacing bytes with a different string.
Anyone with a Base64 decoder can read Base64 content. Never use Base64 alone to protect passwords, tokens or confidential messages. If you need genuine encryption, use the AES-GCM text encryption tool and understand its limitations.
Base64 vs Base64URL
Both represent bytes. Standard Base64 uses +, / and optional padding =; Base64URL uses -, _ and often removes padding. They are not always interchangeable in strict protocols. Use the format your system specifies.
Frequently asked questions
Does Base64 make a string smaller?
No. Base64 usually grows the data by about one third. Its purpose is to transport binary data through text-oriented systems, not to compress it.
Can I encode Chinese, emoji or accents?
Yes. The tool converts Unicode text to UTF-8 first, so multilingual text works without the Latin-1 restrictions of calling btoa on raw Unicode strings.
Why is my Base64 invalid?
Common causes include missing or extra padding, unsupported characters, a truncated string or decoding arbitrary binary bytes as UTF-8 text.
Is my input sent to a server?
No. The conversion runs directly in your browser. The site still uses a hosting provider to serve files; avoid placing sensitive information in any unnecessary online tool.