Quick start
- Choose Encode when starting with readable text.
- Choose Decode when starting with Base64.
- Paste the text into the input field and run the tool.
Best uses
These are the situations this tool is meant for. If your task is close to one of these, the examples and notes below can help you choose the right inputs.
- Encode a short text value into Base64.
- Decode a Base64 string back to readable text.
- Check API examples, headers, payloads, and data snippets.
- Work locally without sending the text to a server.
What this calculator is solving
The Base64 tool encodes text as UTF-8 bytes before converting to Base64. It can also decode Base64 back into UTF-8 text when the data is valid text.
You do not need to memorize the formula first. Start by matching each input label on the calculator to the number, date, unit, or setting you actually have.
The formula in plain language
In plain language: Base64 represents bytes using 64 printable characters and padding. This tool converts text to UTF-8 bytes before encoding and decodes valid UTF-8 after Base64 decoding. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
If that sounds abstract, use the example cards on the calculator page. They show a complete set of inputs and the kind of answer you should expect.
How to read the answer
Read the headline result first. Then look at the smaller supporting lines because they explain the parts behind the answer, such as totals, units, ranges, or formula steps.
- The main answer is the encoded or decoded text.
- Input and output length help you check whether the conversion looks reasonable.
- Mode confirms whether you encoded or decoded.
Common mistakes to avoid
If the answer looks strange, the most likely cause is a small input mismatch: the wrong unit, date, weight, scale, mode, or policy assumption.
- Do not treat Base64 as encryption.
- Do not paste secrets into tools unless you trust the environment.
- Decode mode expects Base64 that represents valid UTF-8 text.
Research and references
These references shaped the calculator assumptions, unit choices, or safety notes.
Examples from the calculator
SGVsbG8gdG9vbHM=
Hello tools
Base64 output with padding if needed
FAQ in plain language
When should I use the Base64 Encode / Decode?
Use it when your task matches one of these common needs: Encode a short text value into Base64. Decode a Base64 string back to readable text. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Base64 Encode / Decode doing with my inputs?
In plain language: Base64 represents bytes using 64 printable characters and padding. This tool converts text to UTF-8 bytes before encoding and decodes valid UTF-8 after Base64 decoding. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What should I double-check before trusting the answer?
Base64 is encoding, not encryption. Do not use it to hide secrets, passwords, tokens, or private data. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Related tools
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- Password Generator Generate strong random passwords with length, character sets, and ambiguity controls.
- Hex Calculator Add, subtract, multiply, divide, and convert hexadecimal numbers.
Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to paste the expression and result into notes, homework, a message, or another document. Check the units and assumptions before copying.