Base64 represents binary data as text by mapping every three bytes to four characters, making the output roughly 33% larger than the input. It is reversible encoding with no key involved, not encryption — anyone can decode it instantly, so it must never be used to protect passwords or secrets.
Last updated 2026-07-30
Convert between plain text and Base64 in both directions. Handy for inspecting JWT payloads, data URIs and encoded configuration values.
How to use Base64 Encoder and Decoder
Choose a direction — Switch between encoding and decoding.
Enter your input — Paste the text or Base64 string to convert.
Copy the output — The result updates immediately and can be copied in one click.
Frequently asked questions
Is Base64 encryption?
No, and this is an important distinction. Base64 is reversible encoding with no key involved — anyone can decode it instantly. Never use it to protect passwords or secrets.
Why is my encoded string larger than the input?
Base64 represents every three bytes as four characters, so output is roughly 33% larger. That overhead is the cost of making binary data safe to transmit as text.
Are my files uploaded to a server?
No. Every conversion runs inside your own browser using JavaScript and WebAssembly. Your files never leave your device, which means there is nothing for us to store, read, or leak.
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