About Base64 for text
Base64 encodes binary data as ASCII text so it can travel through email, JSON fields, or URL-safe channels. This utility focuses on UTF-8 text: it is ideal for quick experiments with JWT segments, small blobs embedded in configuration, or debugging serialization layers—without installing a desktop client.
Encoding uses the browser’s built-in binary primitives so your string never leaves the device. Always treat decoded material as sensitive if it originated from production systems.
Typical use cases
- Checking whether a token is valid Base64 before you decode it elsewhere.
- Embedding short Unicode strings in environments that only tolerate ASCII.
- Comparing encoder output with another language’s standard library for parity tests.
How to use this page
- Paste UTF-8 text on the left when you need an ASCII-safe representation.
- Click Encode to generate Base64. Non-Latin characters are supported through UTF-8 normalization.
- Click Decode when the left field already contains Base64 text.
- Use Swap to move the output back into the editor for chained operations.
- Copy the final string once you verify the transformation is correct.
Limitations
Extremely large strings may hit memory limits in the tab. For big files, prefer streaming tools or command-line utilities. This page is optimized for developer-sized snippets, not multi-megabyte archives.
Frequently asked questions
- Why does decode fail?
- Padding must be correct and the alphabet must be standard Base64. Remove whitespace or URL-safe variants unless you pre-normalize them.
- Is this URL-safe Base64?
- No. This encoder follows the standard alphabet. Replace
+//manually if a downstream system requires URL-safe form. - Does encoding encrypt data?
- No. Anyone can decode Base64—it is encoding, not encryption.
- Can I encode binary files?
- Use the dedicated Image → Base64 tool for files. Plain text mode assumes UTF-8 string input.