Base64 Decode

Decode Base64 strings to text, files, images, and binary data online without uploading input. Supports charset selection, Base64URL, data URIs, and browser-only processing.

Local processing · zero upload
Quick samples
Your data never leaves your browser.
Clipboard or fileProcess in browserPreview, copy, or downloadCtrl+Enter

Decode Base64 to text, files, images, PDFs, and bytes.

Use charset options when the decoded text is not UTF-8.

All processing runs in the browser. Your input never leaves this device.

What this decoder returns

A Base64 string decodes back to bytes. When those bytes are text, the output appears as readable text. When the bytes look like an image, PDF, or other binary file, the tool shows the detected type and lets you download the decoded bytes.

SGVsbG8sIFdvcmxkIQ== -> Hello, World!

Common decode failures

Most decode failures come from copied whitespace, missing padding, URL-safe characters, or a data URI prefix mixed with the payload.

  • Use Base64URL mode for values from JWTs, OAuth, filenames, or URL parameters.
  • Use the repair tool when padding is missing or the input includes line breaks.
  • Change the character set when decoded text looks garbled but the Base64 syntax is valid.

Privacy boundary

The decode operation runs in the browser. The pasted value is not uploaded, logged, analyzed, stored, or sent to a third-party endpoint.

Why no-upload decoding matters

Base64 often appears in API credentials, JWT payloads, config files, screenshots, PDFs, and log fragments. Keeping the decoder local avoids sending those values through a remote file processor when you only need a quick conversion.

  • Text input is decoded with browser APIs after the page loads.
  • File mode reads bytes from the local File API instead of uploading the file.
  • Downloads are generated as browser blobs on your device.