How to use the base64 encoder & decoder
Base64 represents binary bytes using a small alphabet of printable characters. This online Base64 encoder first converts your text to UTF-8 bytes, then encodes those bytes so they can travel through text-oriented systems. The decoder reverses that process and displays valid UTF-8 text. Accented letters, emoji, and non-Latin scripts are supported without the character corruption caused by treating Unicode text as single-byte characters.
Paste your input and choose Encode Base64 or Decode Base64. Enable URL-safe Base64 when working with values that use hyphens and underscores instead of plus and slash characters. URL-safe encoding omits trailing padding. The decoder accepts correctly padded or unpadded input and ignores ordinary spaces, tabs, and line breaks. It rejects malformed alphabets, padding, and noncanonical padding bits.
Use the copy button for a request field or download a text file for later inspection. The input limit is one MiB of UTF-8 data. This is a text converter: decoding an image, archive, or arbitrary binary payload can fail because those bytes are not UTF-8. For binary assets, use a file-oriented decoder instead.
Frequently asked questions
Is Base64 encryption?
No. Base64 is a reversible representation of bytes, with no secret key or confidentiality. Anyone who has the encoded text can decode it. Do not use encoding to protect passwords, credentials, or private documents.
Is my text sent to a server?
No. Encoding and decoding run in this page using browser APIs. The tool does not upload your text or save it in browser storage. Copying or downloading is an explicit action that you control.
Why does decoding fail?
The input may contain invalid symbols, incorrect padding, or bytes that are not valid UTF-8 text. Check whether the source uses Base64url, select the matching option, and remove surrounding quotation marks or data-URL prefixes before decoding.