Online Base64 Decoder

Decode Base64 to text.

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How to use

Paste or type your input in the left editor
Adjust options in the toolbar if available
Copy or download the output from the right pane

This free online tool runs entirely in your browser. No sign‑up, no server uploads.

About Base64 Decode

Decode Base64 to text.

The Base64 decoder strips any whitespace from the input, then processes the string in groups of four characters. Each character is mapped back to its 6-bit value using the Base64 alphabet lookup table, and four 6-bit values are combined into three bytes of output. Padding characters (=) at the end indicate that the final group contains fewer than three bytes. The resulting byte stream is then interpreted as UTF-8 text or rendered as binary content depending on the data type.

Use the left editor to enter your data. The output updates in real time. You can copy, clear, download, or expand either pane.

Tip: Use the search bar to quickly switch between tools.

Sample text

Hello, 世界

Example input shown above. Output appears in the right pane instantly.

Why this tool?

Feature	Base64 Decode	Typical alternatives
Free online tool	Yes	Often yes
Client‑side only (privacy)	Yes	Varies
No sign‑up required	Yes	Varies

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FAQs

Can I decode Base64 strings back to readable text?

Yes. Paste any Base64-encoded string and the decoder will convert it back to the original text. The decoder handles standard Base64 and URL-safe Base64 variants, automatically detecting the encoding style used.

Can I decode a Base64 image and view it?

Yes. If the decoded data is an image (PNG, JPEG, GIF, SVG, WebP), the decoder can display it directly in the browser. This is useful for inspecting Base64-encoded images from data URIs, API responses, or database records.

What happens if the Base64 string is corrupted or invalid?

The decoder validates the input and reports errors if the string contains invalid characters or has incorrect padding. Common issues include missing padding characters (=) or non-Base64 characters mixed into the string.

Can I decode Base64 data from JWT tokens?

Yes. JWT tokens consist of three Base64url-encoded segments separated by dots. You can paste individual segments into the decoder to inspect the JWT header and payload claims. Note that JWTs use URL-safe Base64 without padding.

Does the decoder handle line breaks in the Base64 input?

Yes. The decoder automatically strips whitespace and line breaks from the input before processing. Base64 strings from email MIME attachments often contain line breaks every 76 characters, which are handled transparently.