How to Use the Base64 Data URI Analyzer & Tester
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Paste a `data:...;base64,...` string into the input area.
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The analyzer extracts the MIME type, character set, and encoding scheme.
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View the raw binary byte size vs Base64 character byte size, highlighting the ~33% transfer penalty.
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Preview the rendered image, SVG, or decoded text directly on the canvas.
Practical Example & Use Case
Common Real-World Scenario
Checking whether inlining a 15 KB icon into a CSS stylesheet saves enough HTTP requests to justify the 20 KB Base64 transfer size.
Technical Notes & Limitations
Browser Engine Architecture
All decoding is performed in browser memory via standard DataView and Blob decoders.
Frequently Asked Questions
Why do Base64 data URIs take ~33% more bytes?
Base64 encodes every 3 binary bytes (24 bits) into 4 ASCII characters (32 bits), creating a 4/3 = 133.3% size increase.