About this tool
Base64 Decoder — Decode Base64 strings back to plain text or download as file. Free, fast and private. Runs entirely in your browser at Quick Calci Tools.
Examples
Common scenarios for the Base64 Decoder.
Decode hello world
- base64
- SGVsbG8sIHdvcmxkIQ==
Plain text: Hello, world!
Strip data-URL prefix
- base64
- data:image/png;base64,iVBORw0KGgo…
Decoder ignores MIME prefix and outputs bytes or download link.
Invalid padding
- base64
- SGVsbG8
Error or auto-pad message depending on strict mode.
Who uses the Base64 Decoder?
Common scenarios and audiences for this tool.
API consumers
Turn error payloads that embed Base64 blobs into readable fragments.
QA testers
Inspect attachment bodies returned by legacy SOAP services.
Mobile devs
Decode push notification custom data during on-device debugging.
Teachers
Show reverse encoding after students run the encoder.
Ops
Recover config fragments from backup dumps.
Frequently asked questions
Everything you need to know about the Base64 Decoder.