Input is rejected
remove surrounding quotes, confirm the Standard/URL-safe setting, check padding and verify that the value was not truncated.
Base64 Encoder and Decoder
Encode or decode text and files with standard or URL-safe Base64. Inspect byte length and padding, then copy or download the result.
Base64 utility · Fast, exact Base64 conversion
What this tool does
Use this page to turn UTF-8 text or file bytes into Base64, reverse a Base64 value, or inspect padding and byte counts. Select Standard for the normal alphabet or URL-safe when the receiving system expects Base64URL.
Convert now
1
Enter or upload
Paste text or choose a file
2
Choose an action
Encode, decode or inspect
3
View results
Review output and byte details
1. Input
0 characters
2. Action
3. Output
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4. Quick actions
5. Base64 information
DescriptionBase64 represents bytes as text; it is not encryption.
AlphabetA-Z, a-z, 0-9, +, /, =
Input size0 characters / 0 bytes
Output size0 characters / 0 bytes
PaddingUses = to complete a four-character group.
StatusReady
How it works
Input bytes
101010 111100 110101 ...
Split into 6-bit groups
101010 111100 110101 ...
Convert to indexes
42 60 53 ...
Base64 characters
q 8 1 ...
How to use the converter
Paste the source value or choose a file supported by this page.
Choose Encode or Decode, then select Standard or URL-safe Base64.
Review the output and byte information, then copy or download the result.
Output and format behavior
The page handles encoding, decoding and inspection. Standard Base64 uses the RFC 4648 alphabet; the URL-safe form substitutes - and _ for characters that are awkward in URLs.
Use Standard Base64 for the normal RFC 4648 alphabet. Use URL-safe only when the receiving system expects Base64URL; padding rules can differ by protocol.
Expert tip
Choose the variant from the receiving specification, not from guesswork. Base64URL is common in tokens and URLs, while many APIs still require standard Base64.
When this is useful
Typical workflows include:
- Place a value in a configuration field that accepts text but not arbitrary bytes or line breaks.
- Prepare an exact payload for an API request, webhook fixture or integration test that expects Base64 text.
- Inspect or compare a small payload when the original representation is opaque or difficult to paste safely.
Limitations and safety
Important constraints:
- Base64 normally adds about one third to the byte payload, before any data-URL prefix or surrounding markup.
- Base64 is reversible encoding, not encryption. Anyone who receives the string can decode the original bytes.
Troubleshooting
Decoded text is unreadable
the bytes may not be UTF-8 or may be binary. Inspect the same payload with the hex or binary page.
Frequently asked questions
Is Base64 encryption?
No. Base64 is reversible encoding and must not be used as a secrecy or access-control mechanism.
What is the difference between standard Base64 and Base64URL?
Standard Base64 uses + and /. Base64URL uses - and _ and may omit padding; choose the form required by the receiving system.
Why is the Base64 output larger?
Base64 maps every three input bytes to four output characters and may add padding, so the payload is normally about one third larger.
Does it work on mobile?
You can open the page in a modern mobile browser. File selection, memory use and downloads vary by device, so use a small input for mobile workflows.
Related Base64 tools
Continue with the localized page that matches the next operation:
Convert UTF-8 text to Base64Convert Base64 to UTF-8 textConvert image to Base64Convert Base64 to image
Paste your input above, run the conversion, and copy or download the result.