How to Convert Hex to Decimal in Your Browser

To convert a hexadecimal number to decimal, paste the hex value into the ByteTools Hex to Decimal converter and read the base-10 result instantly — an optional 0x prefix is stripped automatically and even 64-bit values convert exactly. Hexadecimal is base-16, so every digit runs from 0 to F (where A–F stand for 10–15), and decimal is the everyday base-10 you already use. This guide walks through the exact steps and the small details that trip people up.

Convert hex to decimal in four steps

1. Paste or type the hex value. Drop it straight into the input box — from a debugger, a color picker, a memory dump or source code.
2. Leave the 0x prefix if it is there. A leading 0x or 0X is ignored automatically, so both 0xFF and FF return 255.
3. Read the decimal result. The base-10 value updates live as you type — no button to press.
4. Copy with one click. The copy control puts the decimal value on your clipboard, ready to paste anywhere.

Case does not matter: ff, Ff and FF all produce the same answer, so you never have to normalise your input first.

How the conversion actually works

Each hex digit represents four bits and a power of 16. Reading right to left, the first digit is multiplied by 16⁰ (1), the next by 16¹ (16), the next by 16² (256), and so on. The tool sums those products to give the decimal value. For 2AF that is (2 × 256) + (10 × 16) + (15 × 1) = 512 + 160 + 15 = 687.

Hex	Working	Decimal
0xA	10 × 1	10
0xFF	15 × 16 + 15	255
0x100	1 × 256	256
0x2AF	2 × 256 + 10 × 16 + 15	687

Why huge values still convert exactly

Ordinary JavaScript numbers lose precision past 53 bits, which quietly corrupts 64-bit addresses, hashes and cryptographic constants. This converter uses BigInt instead, so a long SHA value or a full 64-bit pointer converts to its exact decimal form with no rounding and no switch to scientific notation. If you type an invalid character — a stray letter beyond F, say — the tool reports a clear error rather than handing you a wrong number.

Private and offline by design

Every conversion happens locally in your browser with JavaScript. Nothing you paste is uploaded, logged or stored, so sensitive addresses and internal values never leave your machine. Because there is no server round-trip, the tool keeps working even with your connection off once the page has loaded.

Try the Hex to Decimal converter — free and 100% in your browser.

FAQ

Do I need to remove the 0x before converting?

No. The converter detects and strips a leading 0x or 0X for you, so you can paste values exactly as they appear in code, debuggers and hex editors without cleaning them up first.

What happens if I paste an invalid hex string?

If the input contains a character outside 0–9 and A–F, the tool shows a clear error instead of guessing. That protects you from a silently wrong result caused by a typo or a stray copy artifact.

Can I convert lowercase hex like ff or deadbeef?

Yes. Hex digits are case-insensitive here, so lowercase, uppercase and mixed-case all convert to the same decimal value.

Is there a limit to how large a value I can convert?

There is no practical size limit. BigInt handles arbitrarily large integers exactly, so 64-bit values and long hashes convert without losing a single digit.

Related free tools

• Decimal to Hex — convert the other direction, base-10 back to base-16.
• Binary to Decimal — turn base-2 strings into decimal.
• Decimal to Binary — see any number in bits.
• RGB to HEX Converter — for hex color codes.

Built by ByteVancer

ByteTools is a free product of ByteVancer, a software and web development studio that builds web apps, SaaS platforms and custom software. If you need engineering help beyond a quick converter, explore what ByteVancer can build for your team.