What is Base64?
Base64 is an encoding format that represents binary data with text characters. It is not encryption, compression or hashing. Anyone with the encoded value can normally decode it, so Base64 does not protect confidential information.
Encode and decode UTF-8 text
Text mode converts text to UTF-8 bytes before encoding it. This allows accented characters, non-Latin scripts and emoji to round-trip correctly. You can also decode valid Base64 or Base64URL back to UTF-8 text.
Not every binary Base64 value represents valid UTF-8 text. Use File mode when the decoded value contains binary data rather than text.
Encode and decode files
File mode can encode a file as raw Base64 or Base64URL. Standard Base64 output can also include a Data URL with the file's media type and Base64 payload.
Paste raw Base64 or a Base64 Data URL to create a downloadable file. UtiliBits parses the supplied value locally and does not fetch the URL. Decoded binary content is downloaded as a file rather than automatically displayed or run.
Standard Base64 and Base64URL
Standard Base64 uses + and /. Base64URL uses - and _ instead and commonly omits padding. Base64URL is a Base64 variant, not ordinary URL percent encoding.
Size limits and Base64 overhead
Base64 normally increases binary data size by roughly one third. It does not reduce file size. This utility accepts up to 10 MB of text or a file up to 25 MB.
Your data stays in your browser
Text and files are encoded or decoded in your browser. They are not uploaded to UtiliBits.
Frequently asked questions
What is Base64?
Base64 is an encoding format that represents binary data as text. It is not encryption, compression or hashing, and anyone with the encoded value can normally decode it.
How does Base64 handle text and emoji?
The tool converts text to UTF-8 bytes before encoding it. This supports accented characters, non-Latin scripts and emoji. Binary Base64 that is not valid UTF-8 text should be decoded through File mode.
What is the difference between Base64 and Base64URL?
Standard Base64 uses + and /. Base64URL replaces those characters with - and _ and commonly omits padding. Base64URL is different from URL percent encoding.
Can I encode a file as Base64?
Yes. File mode can produce raw Base64 or Base64URL. For Standard Base64, it can also produce a Data URL containing the file media type and Base64 payload.
Can I turn Base64 or a Data URL back into a file?
Yes. Paste raw Base64 or a Base64 Data URL in File mode to create a downloadable file. UtiliBits parses the supplied value locally and does not fetch a URL.
Does Base64 make a file smaller?
No. Base64 normally increases binary data size by roughly one third. It is an encoding format, not a compression method.
What are the size limits?
Text input is limited to 10 MB, and file input is limited to 25 MB. These limits keep browser-local processing practical.
Are my text and files uploaded?
No. Text and files are encoded or decoded in your browser and are not uploaded to UtiliBits.