Base64 to File Converter

Tool for converting Base64 encoded data to downloadable files

This online Base64 to file converter decodes Base64 data and converts it into downloadable files with automatic file type detection.

Quickly convert Base64 to file and download decoded files in your browser with no server upload.

Base64 Input

About Base64 to File Converter

This tool allows you to convert Base64 encoded data back into downloadable files. It automatically detects common file types from the Base64 signature and supports a wide range of formats including images, documents, archives, and multimedia files.

How it works: The converter analyzes the Base64 data signature to automatically detect the file type and generates a downloadable file with the correct extension. This eliminates the need to manually specify file types in most cases.

Supported file types:

  • Images: JPG, PNG, GIF, BMP, TIFF, WEBP, SVG, ICO
  • Documents: PDF, DOC, DOCX, RTF, XML, HTML, TXT, CSV
  • Archives: ZIP, RAR, GZ, BZ2, 7Z, TAR
  • Audio: MP3, AAC, OGG, FLAC, WAV, M4A
  • Video: MP4, MPG, MKV, AVI, WMV, MOV
  • Fonts: TTF, OTF, WOFF, WOFF2, EOT

Learn more about file signatures at Wikipedia File Signatures and Base64 encoding at RFC 4648.

If the file type cannot be detected, the file will be saved as a .bin file. You can also manually specify the file name with the desired extension.

All conversion is performed locally in your browser - your data never leaves your device.

File Recovery & Data Extraction Applications

Web Development & Asset Recovery

Essential for web developers who need to extract embedded files from applications, recover assets from data URIs, or process Base64-encoded content from various sources.

Development Use Cases:
  • Extract images from data URIs in CSS/HTML
  • Recover files from application databases
  • Process API responses containing file data
  • Convert inline assets to external files
Data Analysis & Forensics

Critical for data analysts, security professionals, and forensic investigators who need to decode and analyze Base64-encoded files from logs, databases, or network traffic.

Analysis Applications:
  • Decode files from security logs
  • Extract attachments from email systems
  • Analyze encoded malware samples
  • Process forensic evidence data
Email & Communication Systems

This Base64 to file converter is valuable for email administrators, support technicians, and anyone working with MIME-encoded attachments or communication systems.

Communication Scenarios:
MIME attachment recoveryEmail backup extractionMessage archive processingSupport ticket filesDocument recoveryBackup restoration

File Format Detection & Technical Implementation

Magic Number Detection

The converter uses magic number detection (file signatures) to automatically identify file types from the first few bytes of decoded Base64 data, ensuring accurate file extensions.

Detection Examples:
  • JPEG files: FF D8 FF (start with these hex bytes)
  • PNG files: 89 50 4E 47 (PNG signature)
  • PDF files: 25 50 44 46 (%PDF header)
  • ZIP files: 50 4B 03 04 (PK signature)
Browser File Handling

Modern browsers support direct file downloads through the File API and Blob objects, enabling seamless conversion without server-side processing.

Browser Technologies:
  • File API - Client-side file creation
  • Blob objects - Binary data handling
  • URL.createObjectURL() - Download links
  • MIME type detection - Content-Type headers
Data Integrity & Validation

The converter includes validation mechanisms to ensure Base64 data integrity and provides error handling for corrupted or invalid encoded data.

Validation Features:
Format validationPadding verificationCharacter set checkSize calculationCorruption detectionError reporting

Security Note: Always verify file integrity and scan downloaded files with antivirus software when processing data from untrusted sources.

For file format specifications, visit FileFormat.Info and for MIME type references, see MDN MIME Types.