Base64 Analyzer

The Base64 Analyzer inspects a Base64 string or data URI, reporting its size and overhead, detected MIME type and dimensions where applicable, and a decoded preview. It is for developers debugging encoded data.

Encoded data is opaque, and you often need to know what it is and how big it really is. Analysing it locally reveals those details without uploading the data.

1. Paste a Base64 string or full data URI.
2. The analyzer reports size, overhead, and detected type.
3. Review the decoded preview where the content allows.
4. Use the details to debug or verify the data.

• Size and encoding-overhead report
• MIME and dimension detection
• Decoded preview where possible
• Runs locally — Base64 Analyzer

• Checking what an unknown Base64 blob contains
• Measuring the real size and overhead of encoded data
• Confirming the MIME type of a data URI
• Debugging an inlined asset that renders wrong

• Paste the complete string so the size and overhead figures are accurate.
• Remember Base64 is not encryption; treat encoded secrets as exposed.
• Use the detected MIME type to confirm a data URI is built correctly.

• Assuming Base64 is encrypted; it is encoding and can be decoded by anyone.
• Forgetting that encoding adds about a third to the original size, which the overhead figure shows.
• Pasting only part of a long string, which skews the analysis.