Six things it does precisely.
Five bases at once
Binary (2), octal (8), decimal (10), hexadecimal (16), and Base62 (0–9 A–Z a–z). Type into any one and the other four follow.
Real-time validation
Each input enforces its base's character set. Drop a 2 into a binary field and the error tells you why, immediately.
Custom Base62 codec
The non-standard one is implemented directly — character-set validation, leading-zero handling, no third-party round-tripping.
Copy any base
Every field has its own copy button. Grab the hex without copying the wrapping label.
State persistence
The last value sticks between sessions. Re-open the app and your conversion is still there.
Large-number safe
Conversion arithmetic uses arbitrary-precision representations — 64-bit and beyond, with no silent overflow.
Four moves to the right base.
Pick an input
Type into the base you have — hex from a memory dump, decimal from a config, base62 from a short URL.
Read the others
The remaining four bases update instantly. Spot the form you need.
Validate as you go
Invalid characters are flagged per-base. Fix the input; the rest re-converge.
Copy the answer
One-click copy on whichever base you needed. Paste straight into the calling code.
The work it actually does.
Memory and registers
Read a hex dump, see what the decimal value looks like, watch the binary at the same time.
Flags and masks
Decimal-quoted bitmasks become legible binary. The "what bit is set" question answers itself.
Short links
Base62 IDs are the workhorse of URL shorteners. Decode one, encode another.
IP and protocol fields
Convert between the binary form of a packet field and its dotted decimal expression.
Hash digests
Hex from sha256 meets decimal in a math doc — without losing precision in transit.
Teaching the bases
Watch the binary and decimal change together; the relationship becomes visible the way it should.
Things people ask before they download.
Which bases are supported?
Five: binary (2), octal (8), decimal (10), hexadecimal (16), and Base62 (0–9, A–Z, a–z).
What characters does each base accept?
Binary: 0–1. Octal: 0–7. Decimal: 0–9. Hex: 0–9 A–F. Base62: 0–9 A–Z a–z. Invalid characters surface an inline error.
What is Base62 used for?
URL shortening, compact identifiers, and any place an integer wants to fit in fewer characters than a UUID.
How is precision handled?
Conversion arithmetic uses arbitrary-precision numbers, so very large values round-trip exactly across all five bases.
Can I convert negative numbers?
Decimal accepts a leading -. The other bases follow conventional unsigned representation; sign is handled via decimal.
Does this require network access?
No. Base conversion is fully local.