Free Base64 Encoder & Decoder — Online Tool
Encode text or data to Base64 and decode Base64 strings back to plain text.
About this tool
Encode any text to Base64 or decode a Base64 string back to readable text instantly. Useful for working with data URIs, HTTP headers, email attachments, and API payloads. Fully browser-based with no data ever leaving your device.
What is Base64?
Base64 is an encoding scheme that converts binary data into a string of 64 printable ASCII characters. It is widely used to transmit binary data over systems that only support text — including HTTP headers, email protocols (MIME), and data URIs embedded in HTML and CSS.
Common Use Cases
Encoding: embed images in HTML/CSS as data URIs, encode credentials for HTTP Basic Auth headers, prepare file attachments for email. Decoding: inspect encoded API tokens, decode values embedded in JWT payloads, read stored binary data from databases or config files.
codeEncode & Decode Instantly
Paste plain text to Base64-encode it, or paste a Base64 string to decode it back to readable text. Both operations run instantly with no server round-trip — your data stays private.
Base64 powers HTTP Basic Auth, data URIs, JWT tokens, and email attachments — all encodable and decodable here in one click.
Quick Usage Guide
- 1Encode plain text to Base64 in one click
- 2Decode Base64 strings back to readable text instantly
- 3Handles Unicode and special characters correctly
- 4Copy result to clipboard with a single button
- 5100% client-side — your data stays private
Frequently Asked Questions
help_outlineWhat is Base64 encoding used for?
Base64 is used to represent binary data in an ASCII string format. Common uses include embedding images as data URIs, encoding credentials in HTTP Basic Auth headers, handling email attachments, and passing binary data in JSON or URL parameters.
verifiedCan I decode any Base64 string with this tool?
Yes, as long as the Base64 string is valid and the decoded result is valid UTF-8 text. If the decoded bytes are not valid UTF-8 (e.g., binary files), the output may contain unreadable characters.
quizDoes this tool handle URL-safe Base64?
Standard Base64 uses + and / characters. If your string uses - and _ instead, it is URL-safe Base64. The tool handles standard Base64; for URL-safe variants, replace - with + and _ with / before decoding.
account_balance_walletIs there a size limit on what I can encode or decode?
No server-side limit exists since everything runs in your browser. You can encode or decode strings of any length your browser's memory supports.