File to Base64 Converter
Encode any file (PDF, ZIP, documents) to a Base64 string for embedding or transmission.
Drag & Drop File or Click to Browse
Supports all file types (Max 15MB)More Base64 Tools
What is the File to Base64 Converter?
Converting files to Base64 enables their transmission through text-only channels. The FileReader API reads the file as raw binary data (ArrayBuffer), then encodes each byte into Base64 characters. Adding a Data URI header (data:mimetype;base64,...) creates a self-describing string that browsers and applications can interpret directly. This is commonly used for embedding PDFs in HTML, attaching files in JSON API payloads, and storing binary data in text-based configuration systems.
How to use the File to Base64 Converter?
- Drag and drop any file onto the upload area, or click to browse your files.
- The tool reads the file locally and converts it to a Base64-encoded string instantly.
- Toggle 'Include Data URI Header' to add the data:mimetype;base64,... prefix for embedding in HTML.
- File metadata (name, size, type) is displayed for reference.
- Click 'Copy' to copy the Base64 string to your clipboard.
Frequently Asked Questions
What file types are supported?
Any file type is supported — PDFs, ZIPs, Word documents, spreadsheets, executables, audio files, and more. The tool reads raw bytes and encodes them regardless of format.
What is the maximum file size?
Files up to 15MB can be encoded. For larger files, consider using a command-line tool or splitting the file into chunks.
What is the Data URI header?
The Data URI header (data:application/pdf;base64,...) tells the browser what type of content follows. Include it when embedding files directly in HTML or when the recipient needs to know the MIME type.
Is my file uploaded anywhere?
No. The file is read locally using the JavaScript FileReader API. All encoding happens in your browser — nothing is sent to any server.