Base64 encoding: text, bytes and UTF-8
Use repeatable examples to understand text encoding without confusing Base64 with encryption or a binary file viewer.
What this tool converts
The tool converts text into UTF-8 bytes and then Base64; decoding reverses that process. Use it to inspect API fields, handle short text and understand transport formats. Base64 does not hide secrets: anyone with the encoded text can decode it. Encoding a password, access token or personal record does not make it safe to publish.
Start with a round-trip check
Enter Hello and select Encode. The result should be SGVsbG8=. Copy it back into the input editor and select Decode; the original text should return. Next, try a short phrase containing non-ASCII characters and emoji to check that the recipient also expects UTF-8. If plain English works but other characters appear garbled, check the agreed character encoding rather than repeatedly encoding the text.
Different byte encodings of the same visible text can produce different Base64 strings. Similar-looking output does not mean the underlying bytes are identical. Line endings, spaces and invisible characters are part of the input. For signatures or checksums, establish the source of the original bytes first.
Standard and URL-safe variants
Standard Base64 can contain plus signs, slashes and trailing equals signs. The URL-safe variant replaces some symbols, and some protocols omit padding. Do not assume text from a JWT or URL parameter can be decoded as standard Base64 without checking its format. This tool is intended for standard Base64 representing UTF-8 text. Follow the relevant protocol when working with another variant.
A decoding error does not always mean corrupt data
Input may be truncated, include a Data URL prefix or copied quotes, or contain invalid Base64. Even valid decoded bytes may not represent UTF-8 text. Archives, images and other binary files cannot be inspected reliably in a text box. Use the image tool or a viewer appropriate for the file type.
If decoding produces unexpected characters, keep the original and ask the data provider to confirm the content type and encoding. Do not paste unfamiliar decoded content into an executable script. Decoding reveals content; it does not establish that the content is trustworthy.
Padding and copying
Trailing equals signs usually provide padding for Base64's grouping scheme; they are not part of the original text. If the length changes after copying, page formatting may have added line breaks or omitted characters at the end. Verify the copying process with a short example before processing real data. Conversion happens in your browser; save anything you need before refreshing the page.