PNG to Base64
Convert PNG images to Base64 encoded strings or data URIs. Embed images directly into HTML, CSS, or JavaScript. 100% private -- processed entirely in your browser, nothing is uploaded.
Drop a PNG file here to encode
or click to select from your computer
One file at a time -- max 5 MB -- processed in your browser
Drop to encode
What is PNG Base64 Encoding?
Base64 encoding converts binary image data into a text string that can be embedded directly inside HTML, CSS, or JavaScript files. Instead of a separate HTTP request to load an image, the browser reads the encoded data inline -- which can improve performance for small images like icons and sprites.
A Base64 PNG is about 33% larger than the original file, so it is best used for small assets (under 5 KB). For large images, link to a compressed PNG via a normal <img src> tag instead so browsers can cache it separately.
100% Private - Browser Only
Unlike most online converters, this tool processes your PNG entirely inside your browser using the JavaScript FileReader API. Your image data is never uploaded to any server -- it goes directly from your disk to the encoded output on your screen.
This makes it safe for sensitive or confidential images. Want to shrink the encoded string first? Use our PNG Compressor to reduce file size, then come back here to encode the result.
How to Use PNG to Base64
- Drop a PNG file into the upload area above, or click "Select PNG" to choose one from your computer (max 5 MB).
- Choose your output format: Data URI (for HTML/CSS src attributes), Base64 string only, CSS url() wrapper, or a full HTML img tag.
- The encoded output appears instantly. Click "Copy" to copy the full string to your clipboard.
- Paste the result directly into your HTML, CSS, or JavaScript file -- no download needed.
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Frequently Asked Questions
Use Base64 for small images (under 5 KB) that are critical to page rendering -- like icons, logos, or small UI elements. Embedding them saves an HTTP request. For larger images, a normal <img> tag pointing to a compressed PNG is better because browsers can cache the file separately.
Base64 encoding converts binary data to ASCII text using a 6-bits-per-character scheme, which increases size by approximately 33%. This overhead is unavoidable. If file size matters, compress your PNG first to minimize the base64 output size.
No. The entire conversion happens in your browser using JavaScript. Your image data never leaves your device. This is different from our PNG Compressor which requires server-side processing, but Base64 encoding is simple enough to run entirely client-side.
Select "Data URI" format, copy the output, and paste it as the src attribute of an <img> tag. For CSS, use the "CSS url()" format which generates the correct background-image: url("data:image/png;base64,...") wrapper automatically. The "HTML img tag" format generates a complete ready-to-paste <img> element.
Base64 encoding increases size by ~33%, so a 5 MB PNG becomes roughly 6.7 MB of text. Very large base64 strings can slow down page loads and editor performance. For large images, compress them first to reduce both the original and encoded size, or use a regular image file reference instead.