File to Base64 Converter
Convert any document, archive, audio, video, or image file into Base64 strings client-side. Or decode Base64 data chunks back into original downloadable files instantly.
Drag & drop any file here, or
Supports PDF, ZIP, DOCX, MP3, PNG, WebP up to 15MB
File Metadata
- Filename
- —
- MIME Type
- —
- Original Size
- —
- Base64 Length
- —
Decoded File Details
- Detected Format
- —
- Approx. File Size
- —
How to Encode and Decode Files
Encoding (File ➡️ Base64)
- Select or drag a file (PDF, ZIP, PNG, etc.) onto the drop zone.
- Select either Data URI (perfect for HTML embed tags) or Raw Base64 format.
- Copy the converted text block or click download to save it as a text file.
Decoding (Base64 ➡️ File)
- Paste your Base64 text string into the input panel.
- Click "Convert back to File". Our script scans binary signatures to identify the proper file suffix.
- Save the recovered binary package directly to your local file system.
Real-World Base64 Use Cases
- Inline Attachments: Easily embed images, XML, or JSON configurations directly inside standalone HTML newsletters where external references would fail to resolve.
- API Data Payloads: Send file structures cleanly inside GraphQL or REST JSON endpoints without having to implement multi-part form payloads.
- Secure Client-side Handling: Because all conversions happen inside sandbox browsers, confidential files are never transmitted to outside networks, satisfying strict privacy policies.
Frequently Asked Questions
What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. This is commonly used to embed images, files, or attachments directly inside HTML, CSS, XML, or JSON documents.
What types of files can I convert?
You can convert any file type up to ~15 MB! This includes images (PNG, JPG, SVG, WebP), documents (PDF, DOCX, TXT), audio/video files (MP3, MP4), and compressed archives (ZIP, TAR).
Is my uploaded file secure and private?
Yes! All file processing occurs 100% locally within your client browser using the HTML5 FileReader API. Your private files are never uploaded to any server or shared with third parties.
How does the Base64 to File decoding work?
When you paste a Base64 string or Data URI, our decoder automatically parses it, detects the file format via its header signature (magic bytes), calculates the original byte stream, and triggers a browser download with the correct file extension.
Technical Specifications
- Leverages the asynchronous HTML5
FileReader.readAsDataURL()method to parse files into standard schemas. - Identifies file formats inside raw base64 arrays utilizing Magic Bytes (hex block headers: PNG =
89 50 4E 47, PDF =25 50 44 46, etc.). - Conversion yields a fixed mathematical payload inflate size of approximately 33% due to binary conversion mappings.