Image to Base64 Converter Online Free — Encode & Decode
Browser-Side · No Upload · Bulk 20 Files · HTML/CSS/JSON/Markdown Output · Decode Tab
Convert any image to a Base64 data URI entirely in your browser — JPG, PNG, WebP, SVG, GIF all supported. Output as raw Base64, HTML <img> tag, CSS background-image, JSON object or Markdown. Switch to the Decode tab to paste any Base64 string and instantly preview & download the original image. Bulk encode up to 20 files at once. No server upload, no login.
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JPG · PNG · WebP · GIF · SVG · BMP — up to 20 files
What is Base64 Image Encoding?
Base64 converts binary image data into a plain text string (data URI). This lets you embed images directly into HTML, CSS or JSON without a separate file — eliminating one HTTP request. A Base64 string is always about 33% larger than the original file, so it works best for small icons, logos and thumbnails under 10 KB.
How to Use Base64 in HTML, CSS and JavaScript
HTML:<img src="data:image/png;base64,...">
CSS:background-image: url('data:image/png;base64,...');
JavaScript:img.src = "data:image/png;base64,...";
JSON API:{ "logo": "data:image/png;base64,..." }
Frequently Asked Questions
What is Base64 encoding for images?
Base64 converts binary image data into text so it can be embedded directly into HTML, CSS, JSON, and other text-based formats.
How do I use Base64 image in HTML?
Select the HTML output option and copy the generated <img src="data:image/..."> tag directly into your webpage.
How do I use Base64 in CSS?
Choose CSS output to generate a ready-to-use background-image:url(data:image/...); declaration.
Can I decode Base64 back to image?
Yes. Paste a Base64 string or complete data URI into the Decode tab to instantly preview and download the original image.
Is Base64 good for large images?
No. Base64 increases file size by roughly 33%, making it best suited for icons, logos, and small graphics.