Base64 Decoder Online - Encode and Decode Base64 Text

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Example

Encode a short text value

Base64 is often used when text needs to travel through systems that expect plain ASCII characters.

Input


                        QuickToolFlow

Output


                        UXVpY2tUb29sRmxvdw==

Decode an encoded message

Decoding is useful when logs, examples, or configuration values contain Base64 text that should be human-readable.

Input


                        SGVsbG8sIFF1aWNrVG9vbEZsb3ch

Output


                        Hello, QuickToolFlow!

Recognize a data URL prefix

If a value starts with a data URL prefix, remove the metadata prefix before decoding the Base64 payload.

Input


                        data:text/plain;base64,SGVsbG8=

Output


                        Decode only the Base64 part: SGVsbG8=

Practical Notes

Base64 is encoding, not encryption. Anyone can decode it without a password or secret key.
Base64 output is usually larger than the original text because it represents binary-safe data as text.
If decoding fails, check for missing padding characters, copied whitespace, or characters that are not part of the Base64 alphabet.
JWTs use Base64Url, which replaces some characters and often omits padding. Decode JWTs with a JWT-specific tool when possible.
Do not store passwords, API keys, or private tokens in Base64 and treat them as protected. Base64 can be reversed immediately.

How to Use

1. Paste plain text or a Base64 string into the input field.
2. Click Encode to convert text to Base64, or Decode to convert Base64 back to text.
3. Use Swap when you want to run the opposite conversion on the result.
4. Copy the output when the result looks correct.

Features

Encodes Unicode text to Base64 safely
Decodes Base64 strings back to readable text
Uses modern TextEncoder and TextDecoder APIs
Shows clear errors for invalid Base64 input
Supports quick swap between input and output
Processes data locally in your browser

Use Cases

Encoding small text snippets for API examples or configuration values
Decoding Base64 text found in logs, tokens, or data URLs
Checking whether copied Base64 content decodes to readable text
Preparing simple examples for documentation and tests
Inspecting the encoded header or payload section of JWT-like tokens
Testing whether a value is Base64 text or another encoded representation

Frequently Asked Questions

Is Base64 secure?

No. Base64 is not encryption and should not be used to hide secrets. It only changes how data is represented.

Why does Base64 sometimes end with equals signs?

The equals signs are padding characters. They help align the encoded output to the correct byte boundary.

Can this encode non-English text?

Yes. This tool uses UTF-8 encoding through TextEncoder and TextDecoder, so Unicode text is handled correctly.

Is my input uploaded when I encode or decode?

No. The conversion runs locally in your browser. QuickToolFlow does not receive the text you paste into this tool.

Can I use this as a Base64 decoder online without uploading data?

Yes. The tool page is online, but the encode and decode operations run in the browser after the page loads. Your pasted text is not uploaded for conversion.

What is the difference between Base64 and Base64Url?

Base64Url is a URL-safe variant often used in JWTs and web tokens. It replaces plus and slash characters with URL-safe alternatives and may omit padding.

Why does decoded output look unreadable?

The original data may be binary, compressed, encrypted, or not actually Base64 text. Base64 decoding only reverses the representation; it does not decrypt or decompress content.