What you can convert
- Base64 decode online (any file type)
- File to base64 (any file type)
- Base64 to PDF
- Base64 to image (PNG, JPEG, GIF, WebP, SVG)
- Base64 to PNG or JPG
- Base64 to JSON, XML, or HTML text
- Base64 to ZIP and other archives
- Base64 to MP3, WAV, and MP4
- Repair corrupted or invalid base64
How to encode a file to base64
- 1. Open base64app and switch to the Encode tab.
- 2. Drop or upload your file (any type).
- 3. Copy the base64 output — enable data: URI or URL-safe if needed.
How to decode base64
- 1. On the Decode tab, paste your base64 string (data URIs and URL-safe base64 are fine).
- 2. Click Decode — base64app detects the file type and repairs the data if needed.
- 3. Preview the result and download the file with the correct extension.
Frequently asked questions
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: 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.
Is base64app free?
Yes, base64app is 100% free to use with no sign-up required.