Base64 Decode and Encode

Question 1

Is Base64 encoding the same as encryption?

Accepted Answer

No. Base64 is an encoding scheme, not encryption. It is fully reversible without any key. Anyone who has the Base64 string can decode it. Never use Base64 alone to protect sensitive data.

Question 2

Why does Base64 output end with '='?

Accepted Answer

The '=' characters are padding. Base64 encodes 3 bytes into 4 characters. If the input length is not a multiple of 3, one or two '=' characters are appended to make the output length a multiple of 4.

Question 3

What is URL-safe Base64?

Accepted Answer

Standard Base64 uses '+' and '/' which have special meanings in URLs. URL-safe Base64 (RFC 4648) replaces '+' with '-' and '/' with '_', and often omits the '=' padding, making it safe to use in URLs and filenames.

Question 4

Can I decode a Base64-encoded image?

Accepted Answer

Yes. Paste the Base64 string (with or without the data:image/...;base64, prefix) and click Decode. The tool will automatically detect image content and display a preview with a download button.

Question 5

Is my data safe?

Accepted Answer

Completely. All encoding and decoding is performed locally in your browser using JavaScript. No data is ever sent to our servers. We do not log, store, or inspect any input.

Question 6

What is the maximum file size?

Accepted Answer

The tool supports files up to 50 MB. For very large files, processing may take a few seconds depending on your device's performance.

Question 7

What character sets are supported?

Accepted Answer

We support Auto Detect plus UTF-8, ASCII, ISO-8859-1 through ISO-8859-16, Windows-1250 through Windows-1258, GB18030, Shift-JIS, EUC-JP, EUC-KR, KOI8-R, UTF-16, UTF-32, and more.

Question 8

What does 'Decode each line separately' do?

Accepted Answer

When enabled, each line in the input is decoded independently. This is useful when you have multiple Base64-encoded values separated by newlines, such as a list of tokens or log entries.

Base64 Decode and Encode

Private Base64 Encoder & Decoder