What is a Base64 data URI?

A Base64 data URI is a way to embed images directly in HTML, CSS, or JSON as text. It starts with 'data:image/[format];base64,' followed by the Base64-encoded image data. This allows images to be embedded without separate image files, useful for email, CSS, or JSON data.

Will Base64 increase my image file size?

Yes, Base64 encoding increases file size by approximately 33%. A 100KB image becomes about 133KB when Base64-encoded. This is because Base64 uses 4 characters to represent 3 bytes of binary data. For this reason, Base64 is best for small images.

Can I use Base64 images in email?

Many email clients support Base64 images, but some don't. Gmail, Outlook, and most modern email clients support them, but there are size limits (typically 1-2MB). For best compatibility, keep Base64 images under 100KB for email. Test in your target email clients before sending.

Is Base64 encoding secure?

Base64 is encoding, not encryption. It's not secure for protecting sensitive data—anyone can decode Base64 easily. Base64 is used for data transmission and embedding, not for security. Don't use Base64 to 'hide' sensitive images—use proper encryption if security is needed.

What's the maximum image size I should convert?

For email, keep images under 100KB before Base64 encoding. For web/HTML, images under 1MB work well. Very large images (over 10MB) create extremely long Base64 strings that can cause browser or email client issues. For large images, use regular image files instead of Base64 for better performance.

Image to Base64 - Encode for Web Free

When to Use This Tool

Use this when:

You need to embed small images in HTML emails (Base64 data URIs work in most email clients)
You want to embed images in CSS files without external image files
You're working with API responses that return Base64-encoded image data
You need to include images in JSON data structures
You're creating data URIs for embedding resources in HTML/CSS without external hosting
You want to embed images directly in HTML without separate image files
You're working with systems that require Base64-encoded image data

Don't use this if:

You need to convert images larger than 10MB (Base64 increases size by 33%, use file uploads instead)
You're embedding images for websites (use regular image files for better performance)
You need to convert images for production APIs (use proper file upload endpoints)
You require Base64 conversion for very large images (use streaming or chunked encoding)
You need to convert many images at once (process them individually or use batch tools)

What is an Image to Base64 Converter?

An image to Base64 converter transforms image files into Base64-encoded text strings (data URIs) that can be embedded directly in HTML, CSS, and JavaScript code. Our converter processes images entirely in your browser — no server upload.

Base64 image encoding is a widely used web development technique: embedding small icons and logos directly in CSS to reduce HTTP requests, including images in email HTML templates (where external images are often blocked), embedding images in JSON API responses, creating self-contained HTML documents, and encoding images for data storage in text-based formats.

This tool is essential for web developers optimizing page load by inlining small images, email developers creating templates with embedded images, front-end engineers building single-file components with embedded assets, API developers encoding images for JSON payloads, and designers creating self-contained SVG or HTML prototypes.

Compared to using command-line tools (base64 image.png), writing custom scripts, or online converters that upload your images, PureXio converts images to Base64 instantly in-browser with zero privacy concerns. The tool automatically generates the complete data URI format (data:image/png;base64,...) ready to paste into your code.

The tool supports all common image formats (PNG, JPEG, WebP, GIF, SVG), shows the original file size vs. Base64 string size (approximately 33% larger), and provides one-click copy of the data URI, raw Base64 string, or ready-to-use HTML img tag and CSS background-image declarations.

Best for: converting images to Base64 data URIs for embedding in HTML/CSS/JS. Outputs data URI, raw Base64, HTML tag, CSS snippet. Instant, private.

How to Convert Image to Base64

Drop your image file (JPG, PNG, WebP, or GIF) or click to browse and select your file

The tool automatically converts your image to Base64 data URI format. Wait for processing to complete

Copy the Base64 data URI to clipboard or use it directly. The data URI includes the image format prefix (data:image/png;base64,...)

Common Use Cases

Convert a small logo (under 100KB) to Base64 for embedding in HTML email templates

Embed images in CSS files using data URIs to avoid external image file dependencies

Include images in JSON API responses as Base64-encoded strings

Embed images directly in HTML without separate image files for simple web pages

Convert images for use in mobile apps that require Base64-encoded image data

Create data URIs for embedding resources in HTML/CSS without external hosting

Convert images for systems that require Base64-encoded data (some APIs, databases)

Features

Convert images to Base64 data URI format instantly

Copy Base64 string to clipboard with one click

Preview the original image alongside the Base64 data URI

Works with JPG, PNG, WebP, and GIF image formats

Data URI format ready for embedding in HTML, CSS, or JSON

100% private—all processing happens in your browser

No file uploads required—everything processes locally

Limitations & Constraints

Maximum file size: 10MB recommended (Base64 increases size by ~33%, very large images create huge strings)

Performance: Base64-encoded images are larger than original files and load slower in browsers

Email clients: Some email clients have size limits for embedded images (typically 1-2MB)

Not for large images: Base64 is inefficient for large images—use regular image files for websites

Batch processing: Process one image at a time. For multiple images, convert them individually.

Troubleshooting

Image conversion fails or shows error

Solution: Ensure the image file is valid and not corrupted. Try opening the image in an image viewer first. Check that the file format is supported (JPG, PNG, WebP, GIF). If conversion fails, try a different browser or use a smaller image file. Very large images may cause browser memory issues. Prevention: Use standard image formats. Keep images under 10MB for reliable conversion.

Base64 string is very long or causes issues when used

Solution: Base64 increases file size by approximately 33%. Very large images create extremely long Base64 strings that can cause issues in HTML, CSS, or email clients. For large images, use regular image files instead of Base64. For email, keep Base64 images under 1-2MB. Consider compressing images first using our Image Compress tool before converting to Base64. Prevention: Use Base64 only for small images (under 100KB for email, under 1MB for web).

Base64 image doesn't display in email or HTML

Solution: Some email clients don't support Base64 images, or have size limits. Test in multiple email clients. For HTML, ensure the data URI format is correct (starts with 'data:image/...'). Some older browsers may not support data URIs. Try using the Base64 string in a simple HTML test file first. Prevention: Test Base64 images in target email clients or browsers before deployment.

Browser crashes when converting large images

Solution: Close other browser tabs and applications to free up memory. Try a different browser (Chrome handles large files better than Firefox). Compress very large images first using our Image Compress tool, then convert to Base64. If crashes persist, use desktop software for images over 10MB. Prevention: Keep images under 10MB. Compress large images before converting to Base64.

Base64 string is too long to copy or use

Solution: Very large images create extremely long Base64 strings. Consider using smaller images, or compress images first to reduce size. For email, use images under 100KB. For web, consider using regular image files instead of Base64 for better performance. If you must use Base64, break very long strings across multiple lines in code. Prevention: Use Base64 only for small images. For large images, use regular image files.