Are my images uploaded anywhere?

No. Encoding happens locally via FileReader. No network requests are made.

What is the difference between Base64 with and without the data-URI prefix?

With the prefix you get a full data URI like `data:image/png;base64,…` ready to paste into HTML or CSS. Without the prefix you get only the raw Base64 string.

Is there a size limit?

There is no hard limit, but very large images (tens of MB) can take a few seconds to encode in the browser. The output Base64 is about 33% larger than the original file.

Image to Base64

Convert any image file to a Base64 string (data URI) in your browser. Choose to include or strip the data-URI prefix, then copy or download the result. Nothing is uploaded.

Processed in your browser · No upload

Loading tool…

Encoding runs entirely in your browser using FileReader.readAsDataURL. Your image is never uploaded to any server.

Ad Slot (tool-image-to-base64)

FAQ

Are my images uploaded anywhere?: No. Encoding happens locally via FileReader. No network requests are made.
What is the difference between Base64 with and without the data-URI prefix?: With the prefix you get a full data URI like `data:image/png;base64,…` ready to paste into HTML or CSS. Without the prefix you get only the raw Base64 string.
Is there a size limit?: There is no hard limit, but very large images (tens of MB) can take a few seconds to encode in the browser. The output Base64 is about 33% larger than the original file.

Related Tools

Base64 to Image
Paste a Base64 string (with or without the data-URI prefix) and see the image instantly. Preview the decoded image and download it as a real file — all in your browser, nothing is uploaded.
Base64 Encoder
Encode any UTF-8 text to Base64 online for free. Processed entirely in your browser — no data leaves your device.
Image Converter
Convert images between JPG, PNG, and WebP in your browser. Keep the original dimensions, choose a quality, and download the result. Nothing is uploaded.
Image Compressor
Re-encode images to JPEG, WebP, or PNG at a smaller size — choose quality and max width. Compression runs entirely in your browser, so your images are never uploaded.
Image Resizer
Resize images to any width and height in your browser. Choose JPG, PNG, or WebP output and keep the aspect ratio with one click. Your image never leaves your device.
PNG to WebP Converter
Convert PNG images to WebP in your browser. Choose lossy quality or lossless mode, preserve transparency, and download a smaller file — nothing is uploaded.