Why is the encoded string much longer than the source file?
Base64 expands binary data, so output is normally larger than the original binary content.
Base64 Image Encoder
Convert images to Base64 data URIs or decode Base64 back to images
Encode Image to Base64
Decode Base64 to Image
When To Use Base64 Images
Data URIs can simplify prototypes and email templates by removing external image requests, but they also increase document size.
- Use small icons inline to reduce additional requests.
- Avoid very large images in Base64 because payload size grows by about one third.
- Keep original files if you need repeatable optimization passes later.
Related tools: QR Code Generator, Hash Generator, URL Encoder.
Base64 Image FAQ
Can I paste a full data URI back into this tool?
Yes. Typical data URI prefixes are supported when decoding image payloads.
Does image conversion happen on a server?
No. The conversion runs locally in your browser.