How do I encode a file to base64?

Open base64app, switch to the Encode tab, then drop or upload your file. The base64 string appears instantly. You can copy it or enable a data: URI prefix or URL-safe alphabet before encoding.

How do I decode a base64 string?

On the Decode tab, paste your base64 string and click Decode. base64app detects the real file type (PDF, image, document, and more), shows a preview, and lets you download the file.

Can base64app convert base64 to a PDF or image?

Yes. base64app automatically detects PDFs, PNG/JPEG/GIF/WebP/SVG images, and many other formats from the decoded bytes, previews them, and offers a download with the correct file extension.

Can it fix corrupted or invalid base64?

Yes. base64app repairs the most common problems automatically: URL percent-encoding (%2B, %2F, %3D), stray whitespace and line breaks, data: URI prefixes, URL-safe characters, missing padding, and invalid characters.

Is base64app private and safe?

The website is completely private: all encoding and decoding on base64app.com happens locally in your browser. Your files and data are never uploaded, stored, or saved when you use the web app. The optional HTTP API (api.base64app.com) is different — POST requests send your payload to our server for processing. We do not store API payloads in a database. See base64app.com/api/ for details.

Base64 Encode & Decode — PDF, Image, File

Free online base64 encoder and decoder

Encode any file to base64, decode base64 to PDF, images, documents, and more — with automatic repair for corrupted base64. Everything runs locally in your browser.

Converters

Base64 decode online
File to base64
Base64 to PDF
Base64 to image
Base64 to PNG
Base64 to JPG
Base64 to JSON
Base64 to ZIP

Learn

Base64 guides · FAQ · HTTP API