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Integer and Base64 Byte Converter
Convert exact integers to Base64 byte sequences and back with explicit signedness, endian order and minimal or fixed byte width.
Integer decimal text, Canonical standard Base64, Signedness, byte order and width controls
integer-base64.json, integer-bytes.bin
Browser only
Runs locally in your browser. Your files, pasted content and generated output are not uploaded. Reset clears this tool’s working data.
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How to use this tool
- Choose the direction, unsigned or signed two's-complement, big or little endian, and minimal or an exact width from 1 through 512 bytes.
- For encoding, enter optional-minus decimal integer text. For decoding, enter canonical standard Base64 with complete padding and no whitespace.
- Select Convert integer byte representation and download both integer-base64.json and integer-bytes.bin.
- Minimal decoding refuses redundant sign or zero-extension bytes. Explicit-width decoding preserves padding or sign extension only at exactly the requested width.
Examples
Unsigned big-endian 12345 uses bytes 30 39 and Base64 MDk=. Signed big-endian 128 needs bytes 00 80.
Limitations
- At most 1,234 integer digits, 512 bytes, 684 Base64 UTF-16 units, 4,096 exact-intermediate digits, 64 KiB combined complete artifacts and 30 seconds. A 684-character input can still decode to a refused 513-byte sequence.
- No leading plus, spaces, exponent, fraction, URL-safe alphabet or noncanonical padding. Unsigned mode rejects negative spelling including -0; signed -0 normalizes to zero while retaining the original input text.
- Minimal zero is one 00 byte. Explicit-width zero uses exactly that many zero bytes. Values must fit the selected signed or unsigned range without truncation.
- Byte representation only: no character-set decoding, encryption, authentication, integer guessing or native-endian inference.
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