免费Base64编码器和解码器
在浏览器中将文本编码为Base64并解码Base64字符串。
Frequently Asked Questions
What is Base64 encoding and why is it used?
Base64 converts binary data to a text-safe format using only 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It's used to embed images in CSS/HTML, encode email attachments, and transmit binary data over text-based APIs.
Is Base64 the same as encryption?
No. Base64 is encoding, not encryption — it changes the format without adding security. Anyone can decode Base64 trivially. Never use Base64 to protect sensitive data; use real encryption (AES, TLS) instead.
How much larger is Base64 output than the original data?
Base64-encoded data is approximately 33% larger than the original. Every 3 bytes of input becomes 4 ASCII characters. A 1 MB image becomes ~1.37 MB as Base64.
What is the difference between standard Base64 and URL-safe Base64?
Standard Base64 uses + and / which are special characters in URLs. URL-safe Base64 replaces + with − and / with _ making it safe for use in URL parameters and file names without percent-encoding.
Can I encode images to Base64 for CSS backgrounds?
Yes. Upload an image and copy the Base64 string, then use it as: background-image: url("data:image/png;base64,YOUR_BASE64_HERE"). This embeds the image directly in CSS, reducing HTTP requests for small icons.
Is the Base64编解码 free to use?
Yes, the Base64编解码 on Allio Tools is completely free with no sign-up or registration required. It works directly in your browser.
How does the Base64编解码 work?
在浏览器中将文本编码为Base64并解码Base64字符串。 No data is sent to a server — everything runs locally in your browser for maximum privacy and speed.
Do I need to install anything to use the Base64编解码?
No installation needed. The Base64编解码 runs entirely in your web browser on any device — desktop, tablet, or mobile.
Is my data safe when using the Base64编解码?
Completely safe. The Base64编解码 processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.
Does the Base64编解码 work offline?
After the page loads for the first time, the Base64编解码 works without an internet connection for all client-side processing. Tools that fetch live external data (such as DNS or network lookups) require an active connection.
Can I use the Base64编解码 output in commercial projects?
Yes. The Base64编解码 is a utility tool and its output carries no licensing restrictions. You are free to use results in any project, commercial or personal.
Does the Base64编解码 follow official standards?
Yes. The Base64编解码 is built to comply with the relevant industry standard or specification for this utility type. If you encounter an unexpected result, verify your input against the specification — edge cases outside the standard may produce undefined behaviour.
Does the Base64编解码 work on all browsers?
Yes. The Base64编解码 is built with standard browser APIs and works on all modern browsers including Chrome, Firefox, Safari, and Edge — on both desktop and mobile. No plugins, extensions, or third-party software are required.
How do I save or export my results from the Base64编解码?
Select and copy the result text to paste into any document or app. For image tools, a Download button saves the file directly to your device. Your browser's built-in screenshot function also captures results quickly. No account or login is required.