This tool runs entirely in your browser. Your content is never uploaded—100% private and secure.
What is Base64?
Base64 is an encoding scheme that converts binary data into ASCII text. It is commonly used to encode data for transmission over media that are designed to deal with textual data, ensuring that the data remains intact without modification during transport.
Base64 Features
- Converts text or binary data to ASCII
- Safe for URLs, emails, and web forms
- Widely used in data serialization and transfer
Application Scenarios
- Embedding images (data URIs) in HTML/CSS
- Encoding binary for JSON / form transport
- Email (MIME) content transfer
- Quick text obfuscation (not security)
Security Notes
Base64 provides zero confidentiality or integrity. Anyone who sees the string can decode it instantly. Do not rely on Base64 to hide secrets; pair with real encryption (e.g. AES-GCM) if protection is required. When embedding large assets, note that Base64 inflates size (~33%).
Base64 encode/decode online free, no upload (FAQs)
FAQs
- Is Base64 encryption?
- No. Base64 is only an encoding. Anyone can decode it back to the original bytes without any secret.
- Why does Base64 increase size by ~33%?
- Base64 maps 3 bytes into 4 ASCII characters, adding overhead. It trades size for safe text transport.
- How do I decode UTF-8 text safely?
- Decode Base64 to bytes and then interpret with UTF-8. In JavaScript, use atob/btoa with proper UTF-8 handling (encodeURIComponent/unescape workaround).
- Does this Base64 tool upload my data?
- No. It runs 100% in your browser (client-side). Nothing is sent to any server.
- When should I use Base64?
- Use it for text-safe transport (emails, JSON, URLs with base64url). Do not use it to hide secrets.