BASE64 TOOL
Encode and decode Base64 data instantly in your browser — 100% private, no server uploads.
Options
Output
History
Frequently Asked Questions
What format is the output?
Are there any usage limits?
Does it work offline?
Which browsers are supported?
How do I encode text to Base64?
How do I decode Base64 back to text?
Is my data sent to a server?
Why do I get a decoding error?
How to Use
Choose Mode
Select Encode to convert text to Base64, or Decode to convert Base64 back to text.
Enter Data
Type or paste your text into the input box. The result updates automatically as you type.
Copy Result
Click the Copy button to copy the encoded or decoded result to your clipboard.
How to Calculate
Encoding uses UTF-8 bytes converted to Base64 via btoa-style logic, so output is about 4/3 the input size with = padding. Decoding reverses the process and flags invalid characters or bad padding instead of guessing.
About the Base64 Tool
The Base64 Tool lets you encode plain text to Base64 format or decode Base64 strings back to readable text. All processing happens locally in your browser using the built-in btoa() and atob() functions — your data never leaves your device.
Base64 encoding is commonly used for embedding binary data in text formats like JSON, HTML, or URLs. This tool makes it easy to quickly encode or decode without any external dependencies or server calls.
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Methodology & feedback
Figures run locally in your browser from the values you enter (page updated ). Estimates are educational only — verify finance, tax and health decisions with a qualified professional (see Disclaimer). Spotted an error? Report it via contact and we correct with a new update date.