Format guide
What is Base64?
Base64 encoding is a text encoding that represents binary data using 64 ASCII characters — common in data URLs, email attachments, and APIs, created by Various. Base64 turns files into safe ASCII text for transport. It is larger than the binary original (~33%). Convert to/from Base64 when embedding assets or moving binaries through text-only channels.
Base64 format specifications
- Full name
- Base64 encoding
- Kind
- text encoding of binary data
- File extension
- .b64 / data URL
- MIME type
- text/plain (encoded payload)
- Developer / standard
- Various
- Compression
- None — encoding expands size ~33%
- Quality model
- Lossless / not lossy
- Container
- No / single bitstream typical
- Common codecs
- —
- Technical sources
- —
- Transparency
- Not supported
- Animation
- No (still / non-animated typical use)
- Typical size
- Varies
- Browser support
- Via download or conversion in modern browsers
- Compatibility
- Universal in programming languages and browsers
Base64 compression & quality
Base64 is an encoding, not a compressor. Expect larger text than the source binary. Decode before editing images or documents.
Quality: Depends on contents
Typical size: Varies
Transparency & animation
Not supported / not applicable.
Not an animation format in typical use.
Base64 metadata
Varies by encoder and toolchain.
Best use cases for Base64
- Data URLs in HTML/CSS
- API payloads that must be text
- Email-era binary transport
- Embedding small assets in JSON
When to avoid Base64
- Long-term file storage
- Large video/files in chat
- Anything where binary download works
Advantages
- Useful for Data URLs in HTML/CSS workflows
- Convertible in-browser with Format Convertly
Disadvantages
- May need conversion for some audiences
- Not universal for every device
Compatibility
Universal in programming languages and browsers
Browsers: Via download or conversion in modern browsers
Software support
- Browsers
- OpenSSL
- Language standard libraries
- Format Convertly
Device support
- Any developer workstation
How to open Base64
Paste into a decoder or convert back to the original file type.
How to convert Base64
Use Format Convertly’s Base64 converters in your browser to encode or decode privately.
Related formats
Base64 tools
Tools extend the format graph beyond one-off conversion — compression, metadata, and utilities for real workflows.
Base64 FAQ
What is Base64?
Base64 is a text encoding that represents binary data using 64 ASCII characters — common in data URLs, email attachments, and APIs. Base64 turns files into safe ASCII text for transport. It is larger than the binary original (~33%). Convert to/from Base64 when embedding assets or moving binaries through text-only channels.
Are my Base64 files uploaded on Format Convertly?
No. Base64 conversion runs in your browser. Files are not sent to Format Convertly servers for processing.