Developer Tools
Decode Base64 Text
Base64 Decoder for encoding or decoding Base64 text and data.
Direct Answer
Use the Base64 Decoder when you have a Base64 string and need to see the original readable text or inspect encoded API data.
When you need to decode Base64
Base64 shows up in places where binary-safe text was needed, and decoding it lets you see what is actually being sent or stored.
- Inspecting the header or payload segment of a JWT
- Reading the value behind a Basic Auth header during debugging
- Checking what a config or environment variable actually contains
- Viewing the raw content of a Base64-encoded API response field
- Decoding MIME email attachments or embedded data URIs
Base64 decoding limits
Decoding only reverses the encoding step, nothing more.
- Decoding is not the same as breaking encryption, since Base64 was never encrypted to begin with
- It does not verify that the original data is authentic, safe, or unmodified
- Binary content like images or files will decode to unreadable bytes, not readable text
- A decoder cannot fix a truncated or corrupted Base64 string, only report the error
How to Use Base64 Decoder
- Paste or type your content into the input box.
- The transformed result appears instantly in the result panel below.
- Click Copy result to copy the output to your clipboard.
- Download .txt saves the transformed text as a file.
- Reset clears everything and lets you start over.
Reference
| Feature | Details |
|---|---|
| Purpose | Transform pasted text into a cleaner or different format. |
| Input | Text, lines, lists, or copied content. |
| Result | Transformed text ready to copy or download. |
| Best for | Cleanup, formatting, list preparation, and copy-paste workflows. |
| Category | Developer Tools |
| Works on | Desktop, tablet, and mobile browsers |
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Frequently Asked Questions
Is decoding Base64 the same as breaking encryption?
No. Base64 was never encrypted, so decoding it is simply reversing a text encoding, not defeating any security measure. Anyone can decode a Base64 string with no key, password, or special access required.
Why did decoding produce garbled or unreadable text?
Two common causes: the original bytes were binary data like an image or file rather than text, so the decoded output is not meant to be human-readable, or the decoded bytes are text but in a different character encoding than expected, such as UTF-16 instead of UTF-8.
Why do I get an error like invalid character or wrong length?
Base64 strings must use only the standard alphabet and be properly padded to a length that is a multiple of 4. Errors usually mean the string was truncated when copied, contains stray whitespace or line breaks, or mixes in URL-safe characters that a standard decoder does not expect.
What is the difference between Base64 and Base64URL when decoding?
Base64URL substitutes hyphen and underscore for the standard plus and slash characters and commonly drops the trailing equals padding. If a decoder does not recognize the URL-safe variant, a string like a JWT segment can fail to decode or decode incorrectly.
Is it safe to paste an API token or credential here to decode it?
The decoding happens locally in your browser, so the value you paste is not uploaded or sent anywhere. It is still good practice to treat tokens as sensitive and avoid pasting production credentials into tools casually, even ones that process everything client-side.
Can decoding reveal a password that was only Base64 encoded?
Yes, instantly and completely. If a password or secret was stored as Base64 instead of being properly hashed or encrypted, decoding it exposes the original value in plain text with no barrier at all.
Why does my decoded text show odd characters for accented letters?
This is typically a UTF-8 versus UTF-16 mismatch. The bytes were encoded assuming one text encoding, but are being interpreted as the other after decoding, which produces mojibake-style garbled characters instead of the correct accented text.
Can I decode Base64 that represents an image?
You can decode the bytes, but viewing them as plain text will look like meaningless garbage since image data is binary, not text. To actually see the picture, use a dedicated Base64 to Image Converter that renders the decoded bytes as an image instead of text.