Image ⇔ Base64 Converter

Convert between image files and Base64 (Data URI)

Encode images to Base64 Data URI or decode Base64 strings back to images. Supports PNG, JPEG, GIF, and WebP formats. Easy drag & drop operation. All processing is done in your browser - no data is stored or transmitted.

How to Use

Convert in 3 easy steps:

Select conversion mode
Choose either 'Image → Base64' or 'Base64 → Image' tab.
Input your data
For image mode, drag & drop or select an image file. For Base64 mode, paste your Base64 string.
Use the result
Conversion results are displayed instantly. Copy Base64 with the copy button, or download the image with the download button.

Privacy Protection: All processing is done in your browser. Image data is never sent to or stored on any server.

Image ⇔ Base64 Converter

📁

Drag & drop image file here, or click to select

Supported formats: PNG, JPEG, GIF, WebP, SVG (10MB max recommended)

Preview

File name

File size

Dimensions

Format

Base64 Encoded Result (Data URI)

Enter Base64 string

Preview

Practical Use Cases for Image Base64 Conversion

Base64 encoding of images is commonly used in web development for the following purposes:

1. Embedding images in HTML or CSS

Embed small icons or logo images directly in HTML <img> tags or CSS background-image properties to reduce HTTP requests and improve page load speed. Particularly useful as an alternative to icon fonts.

2. Alternative to CSS sprites

Instead of combining multiple small images into a single 'CSS sprite' file, encode each image to Base64 and embed in CSS for easier management.

3. Embedding images in HTML emails

Some email clients block external image loading. Embedding important images (like logos) as Data URIs ensures they display reliably.

4. Image transfer via REST API

When sending/receiving image data through JSON APIs, Base64 encoding allows handling binary data as text format. Transfer images in simple JSON format without multipart communication.

5. Offline applications

In Progressive Web Apps (PWA) or Electron apps, embedding Base64-encoded images in HTML ensures images display reliably even in offline environments.

6. Mobile app development

Using Base64-encoded images in cross-platform frameworks like React Native, Ionic, and Flutter unifies image handling across platforms.

What is Data URI? Understanding the Mechanism

Data URI (also called Data URL) is a URL scheme that allows embedding small files like images or fonts directly into HTML or CSS. It converts file content to text using Base64 encoding and represents it as part of a URL.

Data URI Format

Data URI is written in the following format:

data:[MIME type];[encoding method],[encoded data]

Example (PNG):
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA...

Advantages of Data URI

Reduced HTTP requests: No external file requests needed, improving page load speed
Single file packaging: Complete in a single HTML or CSS file for easy distribution and management
Reliable display: Avoids external image link breaks or blocking

Disadvantages of Data URI

Increased file size: Base64 encoding increases data size by approximately 33%
Lower cache efficiency: Updating images requires re-downloading entire HTML/CSS file
Reduced readability: Source code becomes lengthy and harder to maintain

Best Practices

When to Use Data URI

✅ Small icons or logos (5KB or less recommended)
✅ Frequently used decorative images (button backgrounds, etc.)
✅ Important images requiring offline support

When NOT to Use Data URI

❌ Large images (10KB+): File size becomes bloated
❌ Frequently updated images: Poor cache efficiency
❌ Images reused across multiple pages: Duplicated embedding in each page

⚠️ Generally, using Data URI for small images (5KB or less) is recommended. For larger images, standard <img> tags or external file loading is more efficient.

Frequently Asked Questions (FAQ)

What image formats are supported?

All browser-supported image formats including PNG, JPEG, GIF, WebP, and SVG can be converted. PNG and JPEG are most common.

Is there a size limit for image conversion?

No technical limit exists, but for performance and browser memory considerations, 10MB or less is recommended. Practically, images of 5KB or less are most effective.

How much does image size increase with Base64 encoding?

Base64 encoding increases file size to approximately 133% of original (about 33% increase). For example, a 9KB image becomes approximately 12KB Base64 string.

Can transparent PNG images be Base64 converted?

Yes, transparent PNG images can be converted as-is. Transparency information is preserved, so they display correctly with transparency when embedded in HTML or CSS.

How to embed Base64 string in HTML?

Paste directly into <img> tag's src attribute. Example: <img src="data:image/png;base64,iVBORw0KG...">

How to use as CSS background-image?

Paste inside url() function like: background-image: url('data:image/png;base64,iVBORw0KG...');

Are uploaded images stored on the server?

No, all processing is done in your browser. Image data is never transmitted to any server.

Can I use this for commercial websites?

Yes, this tool is completely free and can be used freely for both commercial and non-commercial purposes.