Base64 Encoder/Decoder

Encode and decode text or files to/from Base64 format

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How to Use This Tool

1

Choose Input Mode

Select 'Text' for encoding/decoding text strings, or 'File' to encode files to Base64.

2

Select Base64 Variant

Choose 'Standard Base64' for general use, or 'URL Safe' for web-safe encoding without padding characters.

3

Enter Your Input

For text mode, type or paste your content. For file mode, click to upload any file.

4

Process Your Data

Click 'Encode' to convert to Base64, or 'Decode' to convert from Base64 back to text.

5

Copy or Download Results

Use the copy button to clipboard or download button to save the output as a file.

Pro Tips

  • •Base64 encoding increases data size by approximately 33%
  • •URL-safe Base64 replaces '+' with '-', '/' with '_', and removes padding '=' characters
  • •Use the 'Swap' button to quickly switch between encoding and decoding with your current output
  • •File encoding creates a data URI that includes the MIME type
  • •The tool automatically formats long Base64 strings for better readability

Understanding Base64 Encoding and Decoding

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's commonly used in web development, email systems, and data transmission to ensure that binary data remains intact during transport through systems that only reliably support text content. Base64 encoding converts every three bytes of binary data into four ASCII characters, making it ideal for embedding images in HTML/CSS, storing complex data in JSON, and transmitting files through text-based protocols.

Key Features

Standard Base64 encoding with padding support for maximum compatibility

URL-safe Base64 variant that replaces special characters for web URLs

File-to-Base64 conversion for embedding images and documents

Automatic MIME type detection for data URI generation

Real-time validation of Base64 strings during decoding

Formatted output with line breaks for improved readability

Support for large files with efficient browser-based processing

One-click swap between encode and decode operations

Common Use Cases

Embedding images directly in HTML or CSS files as data URIs to reduce HTTP requests and improve page load times

Encoding binary attachments for email transmission through SMTP servers that only support 7-bit ASCII

Storing small images or icons in JSON APIs and databases that don't support binary data types

Creating self-contained HTML documents with embedded resources for offline viewing or email templates

Transmitting encrypted data or certificates in configuration files and environment variables

Frequently Asked Questions

What is the difference between standard Base64 and URL-safe Base64?

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Standard Base64 uses '+' and '/' characters which can cause issues in URLs. URL-safe Base64 replaces '+' with '-', '/' with '_', and removes padding '=' characters to ensure the encoded string can be safely used in URLs without requiring additional URL encoding.

Why does Base64 encoding increase file size?

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Base64 encoding increases data size by approximately 33% because it converts every 3 bytes of binary data into 4 ASCII characters. This overhead is the trade-off for being able to transmit binary data through text-only channels reliably.

Can I encode large files with this Base64 encoder?

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Yes, this tool can handle large files efficiently using browser-based processing. However, extremely large files (100MB+) may cause performance issues depending on your device's memory. For very large files, consider using server-side encoding tools.

Is Base64 encoding a form of encryption?

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No, Base64 is not encryption and provides no security. It's simply a way to represent binary data as text. The encoded data can be easily decoded by anyone. For security, you need to encrypt your data before Base64 encoding it.

How do I use Base64 encoded images in HTML and CSS?

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You can use Base64 encoded images directly in HTML with <img src='data:image/png;base64,YOUR_BASE64_DATA'> or in CSS with background-image: url('data:image/png;base64,YOUR_BASE64_DATA'). This tool automatically generates the proper data URI format when encoding files.