Base64 Encode / Decode
Encode plain text to Base64 or decode a Base64 string back to readable text — supports Unicode and international characters.
Runs locally · No data sent to server · Free, no signup
About Base64 Encode / Decode
Base64 is an encoding scheme that converts text or binary data into a string of printable ASCII characters using a 64-character alphabet. It is used throughout web development: encoding Basic Auth credentials in HTTP headers, embedding images as data URIs in HTML and CSS, transmitting binary content in JSON payloads, reading encoded values in JWTs and working with email attachments. This tool encodes plain text to Base64 or decodes any Base64 string back to readable text.
How to use Base64 Encode / Decode
Select Encode or Decode from the mode dropdown, paste your input in the text box and click Run. For encoding, enter plain text and receive the Base64-encoded string. For decoding, enter a Base64-encoded string and receive the original text. The result appears instantly in the output box.
When to use this tool
Use this when encoding credentials for a Basic Authorization header, when inspecting Base64-encoded data in a JWT payload or API response, when embedding small images as data URIs, when decoding Base64-encoded email attachment metadata, or when working with APIs that encode binary content as Base64 strings.
Privacy
Base64 encoding and decoding is a common task that is easy to get wrong when done manually, especially for strings containing Unicode characters. This tool handles UTF-8 encoding correctly before Base64 conversion, which most browser-native implementations do not. All processing runs locally — no data is sent to a server.
Frequently asked questions
Does it support Unicode and international characters?
Yes. The tool converts the input to UTF-8 before Base64 encoding, which correctly handles all Unicode characters including accented letters, emoji and non-Latin scripts. Standard browser btoa() does not handle Unicode, but this tool does.
Is Base64 the same as encryption?
No. Base64 is an encoding format, not encryption. It is trivially reversible and provides no security whatsoever. Never use Base64 as a substitute for encryption when security is required.
What is the difference between Base64 and Base64url?
Standard Base64 uses the characters + and / which have special meaning in URLs. Base64url replaces + with - and / with _ for safe use in URLs and filenames without percent-encoding. This tool produces standard Base64 output.
Why is the Base64 output longer than the input?
Base64 encoding expands data by approximately 33%. Every 3 bytes of input become 4 Base64 characters. This overhead is the trade-off for making arbitrary binary data safe to transmit as plain text.