Convert text to Base64 and back. Commonly used for APIs, data URIs, and embedding binary in JSON. Fully client-side.
Convert text to Base64 format
Base64 encoding is a fundamental technique used by developers, API integrators, and IT professionals to convert binary data into a text-based format. This free online Base64 encoder decoder tool allows you to instantly convert text to Base64 and decode Base64 strings back to readable text. Whether you're working with API requests, email attachments, data URLs, or debugging web applications, this secure tool processes your data entirely in your browser—no server uploads, no signup required.
Perfect for developers handling JSON payloads, authentication headers, or data transfer protocols, this Base64 converter supports UTF-8 encoding and handles various file formats. Students learning web development, QA testers verifying API responses, and system administrators managing configuration files will find this tool invaluable for their daily workflow.
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It converts raw binary information into a radix-64 representation using 64 printable characters: uppercase letters (A-Z), lowercase letters (a-z), digits (0-9), plus the symbols "+" and "/", with "=" used for padding.
The encoding process works by taking groups of three 8-bit bytes (24 bits total) and converting them into four 6-bit Base64 characters. This transformation ensures that binary data can be safely transmitted through text-based protocols like HTTP, email (MIME), or stored in JSON, XML, and other text formats without corruption.
Common real-world applications include embedding images in HTML/CSS via data URLs, encoding email attachments, transmitting binary data in JSON APIs, storing credentials in configuration files, and encoding authentication tokens. Base64 encoding increases data size by approximately 33%, but this trade-off is necessary for compatibility with text-only systems.
When working with REST APIs or GraphQL, you may need to send binary data like images, PDFs, or files within JSON payloads. Since JSON only supports text, Base64 encoding allows you to embed binary content as a string. Our Base64 string encoder helps you prepare data for API requests quickly.
Email systems use Base64 encoding (via MIME) to attach files and embed images. When troubleshooting email issues or building email templates, you'll need to encode attachments or decode received Base64 content.
When transferring binary data through text-based protocols (HTTP headers, XML, configuration files), Base64 encoding ensures data integrity. This is especially important for authentication tokens, session IDs, and encrypted payloads.
HTTP Basic Authentication uses Base64 encoding to transmit username:password combinations. While you should never use Base64 for actual security (it's encoding, not encryption), understanding how to encode and decode these headers is essential for API development and debugging.
Frontend developers frequently use Base64 for data URLs in CSS and HTML, embedding small images or fonts directly in code. When debugging, you may need to decode Base64 strings to verify content or troubleshoot encoding issues. This Base64 encoding tool simplifies the process.
Pro Tip: You can press Ctrl + Enter in the input field for quick conversion. Use "Switch to Encode/Decode" to instantly swap between modes while preserving your data.
Input:
Hello, World!Base64 Output:
SGVsbG8sIFdvcmxkIQ==Base64 Input:
V2VsY29tZSB0byBCYXNlNjQ=Decoded Text:
Welcome to Base64When sending JSON with embedded image data:
{
"userId": 123,
"image": "iVBORw0KGgoAAAANSUhEUgAA..."
}The "image" field contains a Base64-encoded PNG. Use this Base64 to text decoder to verify the image data, or encode your own images using our image to Base64 converter.
Base64 encoding is primarily used to convert binary data into text format for safe transmission through text-based protocols. Common use cases include embedding images in HTML/CSS via data URLs, encoding email attachments, transmitting binary data in JSON APIs, storing credentials in configuration files, and encoding authentication tokens in HTTP headers.
No, Base64 is not encryption—it's encoding. Encryption requires a key to decrypt data, while Base64 encoding can be decoded by anyone who knows the format. Base64 is designed for data representation, not security. Never use Base64 to protect sensitive information. For security, use proper encryption algorithms like AES.
Yes, decoding Base64 is safe when using a trusted tool like this one. Our Base64 decode online tool processes all data entirely in your browser—nothing is sent to our servers. However, be cautious when decoding Base64 strings from untrusted sources, as they could contain malicious content. Always verify the source before decoding.
Yes, Base64 encoding increases data size by approximately 33%. This happens because every three bytes of binary data become four Base64 characters. For example, a 3KB file becomes roughly 4KB when Base64 encoded. This overhead is necessary for compatibility with text-based systems but should be considered when working with large files.
Yes, this Base64 encoder decoder is completely free to use with no signup required. There are no usage limits, no hidden fees, and no account creation needed. The tool works entirely in your browser, ensuring fast performance and complete privacy. For related encoding needs, check out our other text utilities and base converter tools.
Yes, this Base64 converter is fully responsive and works on all devices, including smartphones and tablets. The interface adapts to smaller screens, and all features—encoding, decoding, file upload, copy, and download—are available on mobile browsers. Perfect for developers and professionals who need to encode or decode Base64 strings on the go.
Base64 encoding is reversible and provides no security. Anyone can decode a Base64 string using any Base64 decoder online tool. Never use Base64 to protect passwords, API keys, or sensitive data. Always use proper encryption (AES, RSA) for security-sensitive applications.
This tool uses UTF-8 encoding, which supports all Unicode characters including emojis and international text. However, when decoding Base64 that was encoded with a different character encoding (like Windows-1252 or ISO-8859-1), you may see unexpected characters. Always ensure the original encoding matches when encoding and decoding.
This tool supports file uploads up to 1MB for optimal browser performance. For larger files, consider using command-line tools or specialized software. Base64 encoding increases file size by 33%, so a 1MB file becomes approximately 1.33MB when encoded—keep this in mind when working with large datasets.
While this tool processes data entirely in your browser (nothing is sent to servers), be cautious when working with sensitive information on shared computers or public networks. Clear your browser history and close the tab after use if handling confidential data. For production applications, consider using server-side encoding/decoding for additional security.
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Base64 is an encoding scheme that converts binary data into ASCII text format. It's commonly used to encode data for transmission over text-based protocols like email, HTTP, or XML. Base64 uses 64 characters (A-Z, a-z, 0-9, +, /) to represent binary data.
Select 'Encode' mode, paste or type your text in the input field, and click 'Convert'. The Base64 encoded string will appear in the output field. You can also upload a file to encode its contents.
Select 'Decode' mode, paste your Base64 string in the input field, and click 'Convert'. The decoded text will appear in the output field. The tool automatically validates Base64 format and shows errors if the input is invalid.
Base64 is NOT encryption - it's encoding. It doesn't provide security, only data format conversion. Anyone can decode Base64 strings easily. Don't use Base64 to hide sensitive information. All encoding/decoding happens locally in your browser for privacy.
Yes! Our Base64 encoder/decoder is 100% free with no registration required, no usage limits, and no hidden fees. You can encode and decode as much data as you need.
No, all encoding and decoding happens entirely in your browser. We don't store, save, or have access to any data you encode or decode. Your privacy is completely protected.