File to Base64
Upload any file to instantly encode it to Base64 or a ready-to-embed data URI.
Last updated: October 12, 2026
Upload any file to encode
Drag & drop or browse
Base64 Output Frame
Upload any file in the upload workspace to instantly encode it to Base64 — ready to copy, embed, or download as a text file.
File to Base64
Encode any file into Base64 with our File to Base64 converter. Drop in an image, PDF, font, audio clip, or any other file and get back a Base64 string instantly, either as a raw payload for APIs, JSON fields, and tokens, or as a complete data:... URI ready to paste into HTML, CSS, or markdown. The tool shows the original file size, the Base64 character count, the MIME type, and the encoding overhead percentage so you always know what the embed will cost. Results can be copied with one click or downloaded as a .txt file for later use. Sample TXT and PNG files are generated in your browser if you want to try it first. Everything runs locally with FileReader, so files are never uploaded and there is nothing to install.
Why This Tool Exists
What makes this useful — and why I built it this way.
Universal Input: Images, PDFs, fonts, audio, archives, anything encodes.
Two Output Formats: Raw payloads for APIs and complete URIs for embedding.
Transparent Costs: See the ~33% Base64 overhead before you commit.
No Uploads: FileReader encodes everything on your own device.
Instant Sharing: Download the result as a portable text file.
When You'd Use This
Real situations where this tool saves the day.
Web Development: Embed fonts, icons, and small assets directly in CSS.
API Testing: Build Base64 file fields for REST and GraphQL payloads.
Email Templates: Inline images in HTML email without attachments.
Prototyping: Ship single-file HTML demos with zero external assets.
Data Exchange: Move binary files through JSON-only pipelines.
Using File to Base64
It's straightforward — here's how it works.
Drag and drop any file into the upload box (up to 10MB).
Wait a moment while the file is encoded locally.
Switch between Raw Base64 and Data URI output formats.
Review the size overhead before embedding.
Copy the output or download it as a .txt file.
Questions People Ask
Honest answers about how this works.
What is the difference between this and the Data URI to Image Converter?
This tool accepts any file type and focuses on fast encoding with raw Base64 and data URI outputs plus size-overhead stats. The Data URI to Image Converter is image-specific, adding the reverse direction and HTML, CSS, and Markdown snippet exports with SVG optimization.
Does my file leave the browser?
No. Encoding uses the browser FileReader API entirely on your device. Nothing is uploaded, logged, or stored, so confidential documents, private images, and proprietary assets never touch a server.
Why is there a 10MB limit?
Base64 output is about 33% larger than the original file, and very long strings can make the browser tab sluggish when rendering and copying. The 10MB cap keeps encoding instant and the output manageable; split larger assets before encoding.
Why is the Base64 output bigger than my file?
Base64 represents every 3 bytes of binary data as 4 printable ASCII characters, which guarantees a roughly 33% size increase. The inspector shows the exact overhead so you can decide whether embedding or linking the file is the better choice.
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