Does batch mode support binary data?

No. Both modes accept UTF-8 text only. Batch mode processes one value per line and rejects the batch with a line-specific error if a value is invalid; use single-value mode for wrapped Base64 text.

How do I decode Base64?

Choose decode mode, enter a valid Base64-encoded UTF-8 value, and run the conversion. The output is decoded text, not arbitrary binary-file data.

Does Base64 encryption protect a secret?

No. Base64 is an encoding format, not encryption. Anyone can decode it, so do not use it to protect passwords or confidential data.

Is my text uploaded when I convert it?

No. Encoding and decoding use browser APIs locally; the text is not uploaded to SiteIndex.

Can I paste unpadded or URL-safe Base64?

Choose URL-safe mode for hyphens and underscores; URL-safe encoding omits padding and decoding accepts optional correct padding. Standard mode accepts correctly padded or unpadded standard Base64.

DeveloperReady to use

Base64

Encode or decode standard and URL-safe Base64 text in your browser; the conversion does not upload your input.

Guide

Interactive workspace

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Base64 Encoder / Decoder

Alphabet

Standard Base64 and URL-safe Base64 are supported. URL-safe encoding omits padding; decoding accepts optional correct padding. UTF-8 text only; ASCII spaces, tabs, and line breaks are ignored.

aGVsbG8gd29ybGQ=

Batch mode

Convert one value per line in a single pass.

How to use it

Choose encode or decode and select the standard or URL-safe alphabet.
Paste or type UTF-8 text or encoded text in the input field.
Run the conversion and check any validation message before using the result.
Copy the converted text from the output.

What is Base64?

Encode and decode UTF-8 text directly in your browser.

How it works

Browser APIs encode UTF-8 text using either the standard or URL-safe Base64 alphabet. URL-safe output omits padding. Decoding validates the selected alphabet and decoded UTF-8 text; ASCII whitespace is accepted. The Advanced panel converts one value per line and reports the line number if any value fails.

Example input and expected output

Input

hello

Expected output

aGVsbG8=

Common uses

Encode or decode a single value for debugging an API payload.
Convert a list of values in bulk using batch mode.
Inspect Base64-encoded data before pasting it elsewhere.

Limitations

This is a UTF-8 text codec, not a binary-file converter or encryption tool.
Unpaired JavaScript surrogate characters are normalized by TextEncoder. Base64 is encoding, not encryption.

Frequently asked questions

Does batch mode support binary data?: No. Both modes accept UTF-8 text only. Batch mode processes one value per line and rejects the batch with a line-specific error if a value is invalid; use single-value mode for wrapped Base64 text.
How do I decode Base64?: Choose decode mode, enter a valid Base64-encoded UTF-8 value, and run the conversion. The output is decoded text, not arbitrary binary-file data.
Does Base64 encryption protect a secret?: No. Base64 is an encoding format, not encryption. Anyone can decode it, so do not use it to protect passwords or confidential data.
Is my text uploaded when I convert it?: No. Encoding and decoding use browser APIs locally; the text is not uploaded to SiteIndex.
Can I paste unpadded or URL-safe Base64?: Choose URL-safe mode for hyphens and underscores; URL-safe encoding omits padding and decoding accepts optional correct padding. Standard mode accepts correctly padded or unpadded standard Base64.