Encode any file to base64 in your browser
APIs, email, and web apps often need file content as base64. base64app reads your file locally and shows copy-ready output — no server upload.
- Drag-and-drop or click to upload
- Raw base64 or data:<mime>;base64, prefix
- Optional URL-safe alphabet for JWT-style payloads
How it works
- 1. Drop your file into the encoder above or click to browse.
- 2. Copy the base64 output — toggle data: URI or URL-safe if needed.
- 3. Use the Decode tab or any converter page to reverse the process.
Common errors
- File too large for browser memory — try smaller files under ~32 MB.
- Wrong MIME in data URI — pick the correct type when enabling data: URI output.
- Confusing raw base64 with data URI — APIs may expect one or the other.
Frequently asked questions
How do I convert a PDF or image to base64?
Upload the file. The base64 string appears instantly. Enable data: URI for a ready-to-paste data:application/pdf;base64,... string.
What is URL-safe base64?
URL-safe mode uses - and _ instead of + and / — common in JWTs. See our JWT guide in the Learn section.
Is there a file size limit?
Very large files may be slow or fail in the browser. Typical documents encode instantly.
Are my files uploaded?
No. Encoding is 100% client-side.
Is base64app free?
Yes — free with no sign-up.