A data URI embeds file bytes directly in HTML or CSS as a text string starting with data:. The browser renders the image from the string without making a separate HTTP request to fetch an external file.

When should I embed images as Base64?

For small assets under ~5 KB — icons, favicons, SVG logos, inline decorative images, and HTML email template images. Avoid embedding large photos: they bloat your HTML/CSS by ~33%, cannot be cached separately by the browser, and slow down initial page load.

Why does Base64 make the file larger?

Base64 encoding converts every 3 bytes of binary data into 4 ASCII characters, increasing size by approximately 33%. A 100 KB image becomes ~133 KB as a Base64 string. For small files this overhead is acceptable; for large files it negates the benefit of skipping an HTTP request.

Which formats are supported?

PNG, JPG/JPEG, GIF, WebP and SVG are all supported. Drop any of these and get an instant data URI with ready-to-paste HTML and CSS code snippets.

Are my images uploaded to a server?

No. The conversion uses the browser's FileReader API — your image bytes are read and encoded entirely in your browser. Nothing is sent to any server.

📷

Image to Base64 Encoder

Convert images to Base64 data URIs for embedding directly in HTML or CSS. Free, private.

🖼️ Image Tools Free Browser-based

Tool

Drop an image here or browse files

Converts to Base64 data URI instantly — no upload, runs in your browser

JPEG PNG WebP GIF SVG

What Is a Base64 Data URI?

A data URI embeds a file's contents directly into HTML or CSS as a text string: data:image/png;base64,iVBORw0KGgo…. The browser reads the string and renders the image without an extra HTTP request.

When to Use Base64 Embedding

Best for small, frequently used assets — SVG icons, tiny decorative images, email templates, or offline single-file HTML pages. Avoid embedding large photos: a 500 KB JPEG becomes ~667 KB as Base64 and cannot be cached separately.

Image Size	Recommendation
Under 5 KB (icons, favicons)	Safe to embed as Base64
5–20 KB (small graphics)	Consider case-by-case
Over 20 KB (photos)	Use external file + CDN

How to Use the Output in HTML and CSS

After converting, paste the data URI directly into your code:

Context	Syntax
HTML img tag	`<img src="data:image/png;base64,iVBOR…">`
CSS background	`background-image: url("data:image/png;base64,iVBOR…");`
HTML email	Use as an `<img src>` attribute — external images are often blocked by email clients
Inline SVG	Use SVG's `<image xlink:href="data:image/png;base64,…">`

📖 Embed Images in HTML Without External Files

Image to Base64 Encoder

What Is a Base64 Data URI?

When to Use Base64 Embedding

How to Use the Output in HTML and CSS

Frequently Asked Questions