Number Base Converter — DEC/HEX/BIN/OCT/ASCII
Convert between bases 2-36 + ASCII codes. BigInt support for huge numbers, auto-strips 0x/0b/0o prefixes. Useful for bitwise debugging, memory dumps, CS101.
Outputs
— — — — — ASCII / Text ↔ Number
Convert between bases 2-36 + ASCII codes. Supports negative and large numbers (BigInt). Useful for bitwise debugging, memory dumps, and CS101.
Common bases
- Base 2 (Binary): 0, 1 — the computer's native unit.
0b1010= 10. - Base 8 (Octal): 0-7. Rare today — mostly Unix permissions (
chmod 755). - Base 10 (Decimal): 0-9. The default everywhere.
- Base 16 (Hexadecimal): 0-9, A-F. Used for colors (
#FF0000), MAC addresses, memory addresses.0xFF= 255. - Base 36: 0-9, A-Z. Used for short IDs (e.g. shortened YouTube IDs).
When you need base conversion
- Bitwise debugging:
x & 0xFF= mask the last 8 bits — convert 0xFF to binary to see why. - Memory dumps: hex addresses like
0x7FFE_5F30— convert to decimal to compute offsets. - CSS colors:
#C8102E= RGB(200, 16, 46). - Linux permissions:
chmod 755= octal 111 101 101 = rwxr-xr-x. - Encoding: convert text to ASCII codes to debug encoding issues.
BigInt tip
JavaScript's max safe integer is 2^53 ≈ 9 × 10^15. This tool uses BigInt so it converts up to ~10^308. Useful for:
- 128-bit hex UUIDs.
- Cryptocurrency wallet addresses.
- Snowflake IDs (Twitter/Discord/Instagram) — 64-bit.
Who this is for
Fullstack/backend/devops engineers — debug JWT, format JSON/SQL, parse cURL, compute CIDR subnets, draft Mermaid diagrams, write conventional commits… Daily toolkit alongside your terminal and editor.
FAQ
Is my pasted code/token sent anywhere?
No. All TopDev dev tools run 100% client-side — JWT, SQL, JSON, cURL, regex… process in-browser. Disconnect to verify. Safe for internal tokens, production DB queries, API keys.
Does it work offline / install as a PWA?
Tools work offline after the first load. Installable PWA is on the roadmap — for now you can bookmark and use without internet.
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