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Base64 to Image Converter

Decode Base64 or a data URI to an image preview/download, or encode a file to Base64. Free online tool — no sign-up. Runs locally in your browser.

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How to use

Follow these steps for a clear answer.

1

Paste Base64 or pick a file

Drop a data URI / raw Base64, or choose a local image to encode.

2

Preview

Decoded images appear in the preview; check MIME and byte size.

3

Download or copy

Download the image or copy the data URI for HTML/CSS embeds.

Base64 to image converter specification

Version 1.0.0 · Last reviewed 2026-07-29

Definition
Base64 image conversion turns binary image bytes into ASCII Base64 (often as a data URI) and back to a viewable/downloadable image.
What it calculates
Base64 / data-URI image strings ↔ browser image preview; optional file → data URI encode.
Inputs
  • Base64 string or data URI
  • Optional local image file (encode)
Outputs
  • Image preview
  • Normalized data URI / byte length metadata
Formula
data:[mime];base64,[payload] ↔ binary image bytes

Decode a Base64 image or data URI into a live preview, or encode a local image file to Base64 for HTML/CSS embeds.

Data URI shape

data:image/png;base64,iVBORw0KGgoAAAANSUhEUg...
Part Meaning
data: Data URI scheme
image/png MIME type
base64, Encoding
payload Encoded bytes

Prefer data URIs for small icons only—large images bloat HTML and defeat caching.

Assumptions
  • MIME defaults to image/png when omitted.
  • Runs locally; files are not uploaded.
Units
  • Payload: Base64 characters
  • Size: decoded bytes
Boundary conditions
  • Invalid Base64 yields an error / broken preview.
  • Very large payloads may hit browser memory limits.
Example
data:image/png;base64,iVBORw0KGgo... → PNG preview
Validation cases
  • data URI with image/png → mime image/png, positive byte length
  • raw base64 without prefix → defaults mime to image/png
Sources
  • RFC 2397 data: URL scheme
  • RFC 4648 Base64
Last reviewed
2026-07-29
Calculation version
1.0.0
→ Base64 Decoder & Encoder › → SVG viewer & editor › → PNG to JPG ›

Frequently asked questions

Key distinctions behind the tool.

Do I need a data URI prefix?

Optional. Paste either a raw Base64 payload or a full data:image/...;base64,... URI. Without a prefix, image/png is assumed for preview.

Are files uploaded?

No. Encoding and decoding happen in your browser.

Which formats work?

Preview works for formats your browser can display (commonly PNG, JPEG, GIF, WebP). Encoding uses the file you select.