Image to Base64 Converter

An image-to-Base64 converter encodes the raw bytes of a picture as a long string of ASCII characters that you can paste directly into an HTML <img src> attribute, a CSS url(), or a JSON payload. The result is a data URL — a complete, self-contained resource that starts with data:image/png;base64, and continues with the encoded image bytes. Browsers and many backend systems recognise the prefix and render the image as if it had been loaded from an external URL, but without a second HTTP request.

When inlined Base64 images make sense. Email templates historically use data URLs to embed small logos and icons because many email clients block external images by default. Offline HTML pages (a README, an exported report, a canvas screenshot) embed images so the file is a single self-contained artefact. Tiny decorative icons used in one place only (not your icon set) sometimes go inline to avoid the HTTP overhead for under-1-KB assets. SVG data URLs are a particularly common use case: SVG encoded as Base64 works everywhere that accepts an image URL, even in places where raw SVG cannot be used.

When inlining is a bad idea. Base64 encoding inflates file size by about 33% because it represents 3 bytes as 4 characters. A 100 KB PNG becomes ~133 KB Base64, plus the overhead of being duplicated on every page (a file loaded from a URL is cached once). For any image larger than a few KB or that's used across multiple pages, keep it as a separate asset. Data URLs also break browser caching entirely — the image is bundled into the HTML, so it redownloads every page load.

This tool provides four forms of output for every uploaded image. Data URL is the full string including the MIME prefix, ready for src attributes. Base64 only is the raw encoded bytes without the prefix, useful when a system wants naked Base64 (JWT payloads, some API integrations). HTML <img> is a drop-in tag with the alt attribute already populated from the filename. CSS background is ready to paste into a stylesheet's background-image rule.

Privacy: every byte of every image stays in your browser. The FileReader API reads the file as a data URL locally; nothing uploads. That matters for sensitive images — product screenshots before launch, medical or legal documents, personal photos — where pasting them into a third-party converter would mean a privacy risk.

1. Drop or choose images. Up to 10 MB per file, unlimited files per session.
2. Wait a moment. Very briefly — the browser reads each file locally and generates the Base64 string.
3. Pick the format. Data URL, Base64 only, HTML <img>, or CSS background-image.
4. Copy. Paste into your HTML, CSS, JSON, or email template.
5. Note the size overhead. If the output is dramatically bigger than the source, consider whether inlining is really the right choice.

• Batch upload — process multiple images at once.
• Four output formats per image, each with its own copy button.
• File-size comparison (original vs. Base64) with overhead percentage.
• Drag-and-drop or file picker input.
• JPEG, PNG, WebP, GIF, SVG, BMP, AVIF supported.
• Runs entirely in your browser — images never leave your device.