IMAGE base64
readyDrop an image, paste, or pick a file - get a base64 data URL ready to paste into HTML, CSS, or JSON. Or go the other way: paste a data URL to preview the image.
Base64 output
[01] What is base64 encoding?
Base64 turns binary data into a string of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It's how you embed images, fonts, and other binary in text-only contexts: email (MIME), JSON, CSS url(), HTML img src attributes, JWT payloads.
The size cost is ~33% - base64 needs 4 characters for every 3 bytes. So a 30 KB image becomes ~40 KB of base64 text.
[02] When to inline images as data URLs
- Tiny images (under ~5 KB): embed them to skip an HTTP request. The 33% size penalty is less than the round-trip cost.
- Email signatures, MJML templates: embed so they render without external fetching.
- Service workers caching: data URLs survive offline.
[03] When NOT to inline
- Large images: external file with proper caching beats inline once you're past 10 KB.
- Reusable across pages: external URL gets cached once; inlined version downloads on every page.
- SEO image targets: Google can't index inline images for image search.
[04] Privacy
Encoding and decoding both run entirely in your browser. The image is processed via the FileReader API and base64 is computed locally - nothing is uploaded or logged anywhere.
Common questions
Is Image to Base64 Converter free to use?
Yes. The tool runs in your browser at no cost, with no signup required.
Where is the math performed?
Calculations run locally in your browser. Your inputs do not leave your device.
Are the rates and rules current?
We update sources when published rates change. For high-stakes decisions, verify against the official source linked on this page.