converters

Free Image to Base64 Converter — Batch, 7 Formats, Decode & Remote URL

Convert up to 10 images at once to Data URI, HTML img, CSS bg, Favicon, JSON, Markdown, or plain Base64. Fetch remote images by URL. Decode any Base64 or Data URI back to an image.

100% Free
Privacy Focused
Instant Results
Works Everywhere
Image to Base64 Data URI

Convert images to Base64 Data URI. Batch upload up to 10 files, 7 output formats (HTML img, CSS bg, Favicon, JSON, Markdown), decode back to image.

Up to 10 images · PNG, JPEG, WebP, GIF, SVG, BMP, ICO

Drag & drop images here

or click to browse — select multiple files at once

About This Tool

What is Image to Base64 Data URI?

Our Image to Base64 Data URI Converter is the most complete free tool for encoding and decoding images in the browser. Whether you need to embed a logo in an email template, inline icons in a CSS file, or decode a Data URI you received from an API — everything is handled in one place.

Batch-encode up to 10 images at once. Drag and drop a folder of icons or upload multiple product images — each file gets its own card showing a live thumbnail, dimensions, original size, and the exact Base64 overhead percentage. Switch between 7 output formats per image with a single click: full Data URI, plain Base64 string, HTML <img> tag, CSS background-image, HTML <link> favicon tag, JSON object, or Markdown image syntax.

Prefer to avoid downloading first? Use the "From URL" mode to paste any public image URL and encode it directly. Servers that allow cross-origin access are encoded instantly on canvas; CORS-restricted hosts show a clear message.

Decode mode works in reverse: paste any Data URI or raw Base64 string, hit Decode & Preview, and immediately see the image, its MIME type, dimensions, and decoded file size — then download it or copy the URI. All operations happen entirely in your browser; no image data is ever sent to a server.

Features

Powerful Features

Everything you need in one amazing tool

Batch Upload — Up to 10 Files

Drag and drop or browse multiple images at once. Each file gets its own output card with thumbnail, metadata, and format tabs.

7 Output Formats per Image

Switch between Data URI, plain Base64, HTML img tag, CSS background-image, favicon link tag, JSON, and Markdown with a single click.

Fetch Image from URL

Paste a remote image URL to encode it directly without downloading. Supports CORS-enabled public images.

Decode Base64 → Image

Paste any Data URI or raw Base64 string to preview it as an image, inspect metadata, and download the decoded file.

Overhead & Size Stats

See original size, encoded size, and the exact Base64 overhead percentage for each image so you can make informed decisions.

100% Private — No Uploads

All encoding and decoding happens locally in your browser using FileReader and Canvas APIs. Images never leave your device.

Simple Process

How It Works

Get started in 4 easy steps

1

Upload or Paste a URL

Drop up to 10 image files onto the drop zone, or switch to "From URL" and paste a direct image link.

2

Instant Encoding

Each image is read by FileReader and encoded to Base64 immediately in the browser. Dimensions and size stats appear in the card.

3

Pick Your Format

Click any of the 7 format tabs on each card — Data URI, Base64, HTML, CSS, Favicon, JSON, or Markdown — and the output updates instantly.

4

Copy and Use

Hit Copy on any card to copy the formatted output to your clipboard, ready to paste into your code.

Why Us

Why Choose Our Image to Base64 Data URI?

Stand out from the competition

True Batch Processing

Process a whole icon set at once. No other free tool lets you encode 10 images side by side with separate format controls for each.

Instant — No Uploads

Encoding and decoding happen in milliseconds using browser-native APIs. No servers, no latency, no privacy concerns.

Email Templates

Embed logos and images in HTML emails using Data URIs. No external hosting required — images always display correctly.

Developer-Friendly Outputs

Get output in the exact form you need: <img> tag, CSS url(), JSON for APIs, Markdown for docs, or favicon <link>.

Two-Way Conversion

Not just encoding — decode any Base64 or Data URI back to a viewable, downloadable image in one click.

Informed Decisions

Overhead stats show exactly how much larger the Base64 version is, so you can decide when inline encoding is worth it.

Use Cases

Perfect For

See how others are using this tool

HTML Email Templates

Embed logos, banners, and icons as Data URIs in HTML emails so they always display — no external hosting needed.

CSS Icon Sets

Inline small SVG or PNG icons as CSS background-image Data URIs to eliminate HTTP requests for icon sprites.

Above-Fold Critical Images

Inline hero images and logos in HTML to eliminate render-blocking requests and improve Largest Contentful Paint scores.

Progressive Web Apps

Embed assets in PWA install prompts and offline pages so they render without external network requests.

API & JSON Payloads

Use the JSON output to include image data in REST API payloads or configuration files that expect base64-encoded images.

Debug & Inspect Data URIs

Paste a Data URI you received from an API or log file to preview the image, check its format, and download it.

Frequently Asked Questions

Everything you need to know about Image to Base64 Data URI

Up to 10 images in a single session. Drag and drop all files at once or click "Add more" to append additional images after the first upload. Each image gets its own output card with independent format selection and copy button.

Data URI — the full data:image/png;base64,... string ready to use in img src or url(). Plain Base64 — just the encoded string without the data: prefix. HTML img — a complete <img src="..." alt="..." /> tag. CSS background-image — the background-image: url("..."); CSS declaration. Favicon link — a <link rel="shortcut icon"> tag. JSON — a structured object with mime, fileName, and data fields. Markdown — the ![name](data:...) Markdown image syntax.

Base64 encoding converts binary bytes (8 bits each) into ASCII characters (6 bits per character), which means every 3 bytes becomes 4 characters — a 33% size increase. A 10 KB PNG becomes roughly 13.3 KB of Base64 text. The overhead chip on each card shows the exact percentage increase so you can decide if inline encoding is worthwhile.

Yes — switch to the "From URL" method and paste any direct image link. The tool loads the image via a canvas element and encodes it to Base64. This works for images on servers that allow cross-origin requests (CORS). For servers that block cross-origin access, you will see a CORS error — in that case, download the image first and upload it instead.

Switch to "Base64 → Image" mode. Paste either a full Data URI (data:image/png;base64,...) or a raw Base64 string into the text area and click Decode & Preview. The tool renders the image and displays its MIME type, dimensions, and decoded file size. You can then download the decoded image or copy the full Data URI.

Never. All encoding and decoding happens entirely in your browser using the FileReader API and HTML5 Canvas. No image data is ever sent to any server. You can even disconnect from the internet after loading the page and the tool will still work correctly.

Data URIs are best for: small images under 5–10 KB (icons, logos, bullets); HTML email templates (no external URLs); above-the-fold critical images to reduce render-blocking requests; and self-contained HTML files. Use regular image files for: large photos (Base64 adds 33% overhead and prevents caching); images reused on multiple pages; and production websites where HTTP/2 multiplexing makes multiple requests cheap.

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