Base58 and Base62 Encoder
Encode a whole number as Base58, Base62 and Base36, the compact alphabets used for short links, IDs and Bitcoin addresses, or decode any of them back to decimal, exactly at any size.
How to Use
- Choose what you are entering: decimal, hex, Base36, Base58 or Base62.
- Type or paste the value; big numbers such as 2⁶⁴ − 1 are fine.
- Read all three compact encodings and the decimal value side by side.
- The chart compares how many characters each one needs.
- Click any readout to copy it.
Worked Example
1,000,000 in Base62. Divide by 62: 1,000,000 = 16,129 × 62 + 2 → 2; 16,129 = 260 × 62 + 9 → 9; 260 = 4 × 62 + 12 → C (A is 10, so 12 is C); 4 → 4. Reading upwards: 4C92.
1,000,000 in Base58. The remainders are 22, 15, 7 and 5, which in the Base58 alphabet are P, G, 8 and 6 (the alphabet starts at 1, so position 5 is 6): 68GP.
The common mistake: mixing up alphabets. Base58 digits are shifted (its first character is 1, not 0) and skip 0, O, I and l, so decoding a Base58 string with a Base62 alphabet gives a different number with no error at all. Know which alphabet produced a string before decoding it.
Show Work
Formulas
Alphabets for Humans
Satoshi Nakamoto chose Base58 for Bitcoin in 2009, noting that it avoids characters that look alike in some fonts and that a double-click selects the whole string because it has no punctuation. It has since been used by IPFS content IDs, Solana, and many systems that need identifiers people can copy by hand.
Base62 became popular with URL shorteners, which turn an auto-incrementing database ID into a short code: a billion links need only six Base62 characters. Base36, which ignores letter case, is common where codes may be uppercased, such as in some tracking numbers and in Reddit’s post IDs.
About This Calculator
This tool encodes a whole number of any size, entered in decimal or hex, as Base58 (Bitcoin alphabet), Base62 (0–9 A–Z a–z) and Base36, and decodes any of those back. It shows the divisions and compares how many characters each encoding needs. It works on numeric values; byte strings with leading zeros, as in Bitcoin addresses, need Base58Check instead.
Everything runs in your browser; nothing is sent anywhere. For any other base or a custom alphabet, use the arbitrary base converter.
Related calculators: Arbitrary Base Converter, Number Base Converter, and Base64 Encoder and Decoder.
Frequently Asked Questions
What is Base58?
A base-58 encoding whose alphabet is the digits and letters minus four that are easily confused: 0 (zero), O (capital o), I (capital i) and l (lower-case L). It was designed for Bitcoin addresses so they can be read aloud and typed without mistakes, and is now used for many IDs.
What is Base62?
Base 62 using 0–9, A–Z and a–z: every character that is safe in a URL path without escaping, and no punctuation. It packs about 5.95 bits per character, so 1,000,000 is just 4C92. URL shorteners and database IDs often use it.
How do I convert a number to Base58?
Divide by 58 repeatedly and look each remainder up in the alphabet 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz, reading the results from last to first. 1,000,000 ÷ 58 = 17,241 r 22 (P), 17,241 ÷ 58 = 297 r 15 (G), 297 ÷ 58 = 5 r 7 (8), 5 → 6, so it is 68GP.
Is this the same as Bitcoin address encoding?
The alphabet is the same, but a Bitcoin address encodes bytes, not a number: each leading zero byte becomes an extra 1, and a checksum (Base58Check) is added. This tool encodes the numeric value only, which is how most short-ID schemes use these alphabets.
Are there different Base62 alphabets?
Yes. This tool uses 0–9, then A–Z, then a–z, the most common order. Some libraries put lower case before upper case (0–9, a–z, A–Z), which gives different strings for the same number, so check which one a system uses before decoding its IDs.
How do I use the Base58 and Base62 Encoder?
Simply type or paste your value and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Short links
ID 1,000,000 becomes the 4-character Base62 code 4C92.
Readable IDs
1,234,567,890 in Base58 is 2t6V2H, with no 0/O or I/l to misread.
Big numbers
2⁶⁴ − 1 is jpXCZedGfVQ in Base58, 11 characters instead of 20 digits.
Decoding
The Base36 string lfls decodes to 1,000,000.
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