Free Image to Base64 Converter that works offline
Turn an image into a self-contained data URL for a small HTML, CSS or JSON example. The browser reads the bytes locally, shows a preview and lets you copy or download the resulting text.
What this image to base64 converter does
Base64 increases binary size by roughly one third before additional text overhead. Data URLs are convenient for small embedded assets and fixtures, but separate cached files are usually better for large production images.
How to use the Image to Base64 Converter
- Enter or paste a local image file up to 20 MB into the tool.
- Adjust the available options so they match the format and result you need.
- Choose Convert to Base64 and review a complete MIME-labelled data URL before using it.
- Copy or download the result, then clear the page if the input was sensitive.
Common uses
- Embedding a tiny icon in a prototype
- Creating self-contained test fixtures
- Inspecting an image MIME data URL
- Moving a small image through a text-only field
Private processing and offline access
This tool does not submit your input to a conversion server. Processing takes place inside the browser using local JavaScript and standard Web APIs. After the PWA has been installed or cached, the page and its core features remain available without an internet connection. Closing or clearing the page removes unsaved input; the tool does not create an account or cloud history.
Tips for accurate results
- Avoid embedding large photos in production markup.
- Base64 is encoding, not encryption.
- Keep the data URL prefix when the consumer needs to know the image MIME type.
Frequently asked questions
Does the selected image leave my device?
No. FileReader creates the data URL in the browser and no upload request is made.
Why is the Base64 result larger?
Base64 represents every three input bytes with four text characters, adding roughly 33 percent before the prefix.
Can I use the result in an img element?
Yes. A complete image data URL can be assigned to an img src attribute, subject to page security policy and practical size limits.