Image to Base64 Converter

Encode images to Base64 and data URIs in your browser. Files are not uploaded to our servers.

Drop one or more images, or click the zone above to browse.

Why convert an image to Base64?

Base64 turns binary image bytes into plain text so you can drop the result into HTML src attributes, CSS url() values, JSON payloads, or test fixtures without hosting a separate file. It is a common pattern for tiny icons, prototypes, and environments where a single self-contained string is easier than another round trip. For a full conceptual walkthrough, see our Base64 encoding guide.

Encoding is not the same as optimizing: if your goal is a smaller file for the web, start with how image compression works and practical steps in reduce image file size before you inline bytes as text.

Base64 and payload size at a glance

Binary vs encoded size
Base64 adds about 33% versus the same image kept as a binary file on disk or over the wire.
Data URI shape
A usable browser string looks like data:image/png;base64, plus the encoded payload (MIME type matches your source).
HTML and CSS weight
Large embeds inflate document and stylesheet size, which can delay parse and style recalculation.
Caching behavior
Unlike a normal image URL, an inlined data URI does not get its own cache entry as a subresource with a familiar URL key.

What this tool does

Drop or select one or more images and copy either the raw Base64 block or the full data:image/…;base64, string. You can also download the raw payload as a small text file. Encoding runs locally in your browser with the File API; nothing is sent to the API for this step.

  • PNG / WebP / GIF: lossless or transparency-capable sources keep the matching MIME type in the data URI when the browser reports it correctly.
  • JPEG: still common for photos; no alpha channel—see transparency and alpha if you need a cutout.
  • Copy targets: use Copy data URI for src or CSS url(), and Copy raw Base64 when another system already knows the MIME type.

Tradeoffs and safe use

Inlining removes one HTTP request for that asset but pushes bytes into the parent document or stylesheet. That can be acceptable for icons under about 5 KB and tight demos; it is a poor default for multi‑megabyte photos or responsive galleries where optimizing images for the web normally means proper dimensions, modern formats like WebP or AVIF, and normal URLs with caching headers.

If you embed user uploads, remember that EXIF and other metadata may still be inside the file until stripped elsewhere; encoding to Base64 does not remove embedded metadata by itself.

Format choice still matters: PNG preserves sharp edges and alpha but grows quickly for photos; JPEG remains the practical photo container when transparency is not required.

When not to use Base64 embeds

  • Large above-the-fold images: prefer a real URL, responsive sources, and browser caching for LCP-friendly delivery.
  • Email at scale: some clients and spam filters penalize huge inline payloads; test templates even when Base64 is valid.
  • Master archives: keep lossless originals on disk or in object storage; Base64 is a transport or embed representation, not archival magic.

Image to Base64 questions, answered

Does Base64 make an image file smaller?

No. Base64 is an encoding, not compression. Encoded text is roughly 33% larger than the original binary image. If you need a smaller payload, compress or resize the image first, then encode only if you still need an inline data URI.

What is the difference between raw Base64 and a data URI?

Raw Base64 is only the encoded bytes as text. A data URI wraps that string with a MIME type prefix, for example data:image/png;base64, followed by the payload. Browsers need the MIME prefix to interpret the bytes as an image when you paste into src or CSS url().

Can I use a Base64 image in CSS?

Yes. Pass the full data URI inside url(), for example background-image: url("data:image/png;base64,..."). This inlines the asset into your stylesheet, which is practical for tiny icons but hurts caching and bundle size for large bitmaps.

Does transparency survive in a Base64 PNG or WebP?

Yes, when the source file already has an alpha channel and you keep the same format. Base64 does not flatten transparency; it only changes how the bytes are represented as text. Converting to JPEG would drop alpha because JPEG does not carry transparency.

When should I avoid embedding images as Base64?

Skip large photos, hero images, and anything on the critical rendering path where normal URLs, responsive srcset, and CDN caching perform better. Prefer URLs for maintainability, HTTP caching, and smaller HTML payloads. Reserve data URIs for small icons, inline demos, and constrained environments like some email templates.