Convert FB2 to BASE64
Max file size 100mb.
FB2 vs BASE64 Format Comparison
| Aspect | FB2 (Source Format) | BASE64 (Target Format) |
|---|---|---|
| Format Overview |
FB2
FictionBook 2.0
XML-based ebook format developed in Russia. Designed specifically for fiction and literature with rich metadata support. Extremely popular in Eastern Europe and CIS countries. Stores complete book structure including chapters, annotations, and cover images in a single XML file. Ebook Format XML-Based |
BASE64
Base64 Encoding
Binary-to-text encoding scheme that represents binary data in ASCII string format. Commonly used for embedding files in HTML, CSS, JSON, or XML. Essential for data URIs, email attachments (MIME), and transmitting binary data over text-based protocols. Not a compression format. Encoding Text-Safe |
| Technical Specifications |
Structure: XML document
Encoding: UTF-8 Format: Text-based XML Compression: Optional (ZIP as .fb2.zip) Extensions: .fb2, .fb2.zip |
Structure: Encoded text string
Alphabet: A-Z, a-z, 0-9, +, / Padding: = character Size Increase: ~33% larger than source Extensions: .txt, .b64 (text file) |
| Syntax Examples |
FB2 uses XML structure: <FictionBook>
<description>
<title-info>
<book-title>My Book</book-title>
<author>John Doe</author>
</title-info>
</description>
<body>
<section>
<title>Chapter 1</title>
<p>Text content...</p>
</section>
</body>
</FictionBook>
|
Base64 encoded output: PEZpY3Rpb25Cb29rPgog IDxkZXNjcmlwdGlvbj4K ICAgIDx0aXRsZS1pbmZv PgogICAgICA8Ym9vay10 aXRsZT5NeSBCb29rPC9i b29rLXRpdGxlPgogICAg ICA8YXV0aG9yPkpvaG4g RG9lPC9hdXRob3I+CiAg ICA8L3RpdGxlLWluZm8+ CiAgPC9kZXNjcmlwdGlv bj4KPC9GaWN0aW9uQm9v az4= |
| Content Support |
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| Advantages |
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| Version History |
Introduced: 2004 (Russia)
Current Version: FB2.1 Status: Stable, widely used Evolution: FB3 in development |
Introduced: 1987 (RFC 1421)
Current Spec: RFC 4648 (2006) Status: Internet standard Variants: Standard, URL-safe, MIME |
| Software Support |
Calibre: Full support
FBReader: Native format Cool Reader: Full support Other: Moon+ Reader, AlReader |
All Languages: Built-in support
Command Line: base64, openssl Browsers: btoa(), atob() functions Other: Universal encoding support |
Why Convert FB2 to Base64?
Converting FB2 ebooks to Base64 encoding is useful when you need to embed ebook files in web applications, transmit them via JSON APIs, store them in databases as text fields, or include them in email messages. Base64 encoding converts binary or text data into a safe ASCII string format that can be transmitted over text-based protocols without corruption.
FB2 (FictionBook 2) is an XML-based ebook format popular in Russia and Eastern Europe. While FB2 files are text-based XML, Base64 encoding ensures they can be safely embedded in JSON responses, HTML data attributes, or transmitted via systems that only support plain ASCII characters. This is particularly useful for web developers building ebook libraries, API endpoints, or client-server applications.
Base64 encoding is not compression - it actually increases file size by approximately 33%. However, it ensures that your FB2 content can be safely transmitted through any text-based channel without special character issues, line ending problems, or encoding conflicts. The encoded data can be easily decoded back to the original FB2 file when needed.
Key Benefits of Converting FB2 to Base64:
- Web Embedding: Include ebook files directly in HTML data attributes or JavaScript
- API Transmission: Send files through JSON/XML APIs without multipart encoding
- Database Storage: Store binary files in text fields
- Email Safe: Transmit files via email using MIME encoding
- No Special Characters: Only uses safe ASCII characters (A-Z, a-z, 0-9, +, /)
- Reversible: Can be decoded back to original FB2 file perfectly
- Universal Support: Every programming language has Base64 encoding/decoding
Practical Examples
Example 1: Basic FB2 to Base64 Encoding
Input FB2 content (book.fb2):
<FictionBook>
<body>
<p>Hello World!</p>
</body>
</FictionBook>
Output Base64 encoded string:
PEZpY3Rpb25Cb29rPgogIDxib2R5PgogICAgPHA+SGVsbG8gV29ybGQhPC9wPgogIDwvYm9keT4KPC9GaWN0aW9uQm9vaz4=
Example 2: Using Base64 in HTML Data URI
FB2 file encoded as Base64:
PEZpY3Rpb25Cb29rPi4uLjwvRmljdGlvbkJvb2s+
HTML download link with embedded Base64 data:
<a href="data:application/x-fictionbook+xml;base64,PEZpY3Rpb25Cb29rPi4uLjwvRmljdGlvbkJvb2s+" download="book.fb2"> Download Book </a>
Example 3: JSON API Response with Base64
API endpoint returns FB2 as Base64:
{
"success": true,
"filename": "my_book.fb2",
"content_type": "application/x-fictionbook+xml",
"data": "PEZpY3Rpb25Cb29rPgogIDxkZXNjcmlwdGlvbj4KICAgIDx0aXRsZS1pbmZvPi4uLg==",
"size_bytes": 15420
}
JavaScript to decode and download:
// Decode Base64 to binary
const binaryString = atob(response.data);
const bytes = new Uint8Array(binaryString.length);
for (let i = 0; i < binaryString.length; i++) {
bytes[i] = binaryString.charCodeAt(i);
}
// Create download link
const blob = new Blob([bytes], { type: 'application/x-fictionbook+xml' });
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = 'book.fb2';
a.click();
Frequently Asked Questions (FAQ)
Q: What is Base64 encoding?
A: Base64 is a binary-to-text encoding scheme that converts binary data into ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). It's commonly used to transmit binary data over text-based protocols like HTTP, email (MIME), or embed files in JSON/XML/HTML. Base64 is NOT compression - it increases size by ~33%.
Q: Why does Base64 increase file size?
A: Base64 uses 6 bits per character (64 = 2^6), but each character takes 8 bits of storage. This means every 3 bytes of input becomes 4 bytes of output, resulting in a 33% size increase. Padding with '=' characters is added when input isn't divisible by 3.
Q: How do I decode Base64 back to FB2?
A: Use any Base64 decoder. In command line: `base64 -d encoded.txt > book.fb2`. In JavaScript: `atob(base64String)`. In Python: `import base64; base64.b64decode(encoded)`. All programming languages have built-in Base64 decoding functions.
Q: Can I use Base64 for data URIs in HTML?
A: Yes! Data URIs allow embedding files directly in HTML: `data:application/x-fictionbook+xml;base64,[BASE64_STRING]`. This works for download links, but be aware that large files can make HTML pages very large. Best for small FB2 files.
Q: Is Base64 encoding secure?
A: No! Base64 is NOT encryption - it's encoding. Anyone can decode Base64 strings instantly. Don't use Base64 to hide sensitive data. It's designed for safe transport, not security. For security, use encryption (AES, RSA) before encoding.
Q: What's the difference between standard and URL-safe Base64?
A: Standard Base64 uses +/= characters. URL-safe Base64 (RFC 4648) replaces + with - and / with _ (and omits padding =). This prevents issues when Base64 appears in URLs or filenames where +/= have special meanings.
Q: Can I compress FB2 before Base64 encoding?
A: Yes! Compress FB2 to ZIP/GZIP first, then encode. This reduces overall size since compression happens before the 33% Base64 overhead. Example flow: FB2 -> GZIP (smaller) -> Base64. Many APIs do this automatically.
Q: Why use Base64 for API responses instead of file uploads?
A: Base64 allows sending files in JSON/XML responses without multipart encoding. It's simpler for APIs, works with any HTTP method (not just POST), and integrates cleanly with JavaScript. The 33% overhead is often acceptable for small files or when simplicity matters more than bandwidth.