Base conversion here covers unsigned integers and Unicode scalar values. Signed two's-complement layouts, floating-point radix conversion, and arbitrary-precision math beyond browser BigInt limits require specialized tools.

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Base Converter

By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026-06-02· Reviewed by EverydayTools Editorial Team

What is a number base converter?

Number base conversion rewrites the same integer in different positional notations. Binary uses digits 0–1, octal 0–7, decimal 0–9, hexadecimal 0–9 plus A–F, and bases up to 36 use 0–9 and A–Z. Developers use base converters when reading memory dumps, color channels (#RRGGBB), permission bitmasks, and protocol fields.

This tool accepts multiple tokens per line, custom radix 2–36, text↔code points with UTF-8/ASCII/Latin-1, optional 8-bit padded binary, live auto-convert, conversion breakdown, clickable recent history, shareable URLs, and local .txt upload. Large integers beyond JavaScript's safe integer use BigInt for exact results. File upload reads locally in the browser—nothing is uploaded to EverydayTools servers.

Convert unsigned integers and text code points across bases 2–36 in your browser—with live output, BigInt for large values, and share links for team handoffs.

Who uses Base Converter?

Common real-world scenarios where this tool saves time.

Firmware and embedded developers

Inspect register and bitmask values

Jump between hex dump lines and binary bit patterns when reading datasheets or UART logs.

Web and game developers

Decode color and asset IDs

Convert #RRGGBB channels and packed integer IDs between hex and decimal without opening a REPL.

Students and CTF players

Practice radix conversion homework

Verify manual binary↔hex steps and encode short messages as code points for encoding challenges.

Security researchers

Decode large constants and magic numbers

Convert 64-bit hex constants to exact decimal with BigInt instead of lossy floating-point approximations.

Base Converter examples

Decimal 65 to binary and hex

Input

65

Output

01000001 (binary) · 41 (hex) · 101 (octal)

ASCII letter 'A' is code point 65—common when inspecting character tables.

Hex color channel

Input

FF

Output

255 decimal · 11111111 binary

Two hex digits per byte in #RRGGBB colors—quickly verify channel intensity.

Text Hello to hex

Input

Hello

Output

48 65 6C 6C 6F (space-separated hex bytes)

Text mode emits Unicode scalar values in the target base—use UTF-8 encoding for multi-byte characters.

64-bit hex to decimal

Input

FFFFFFFFFFFFFFFF

Output

18446744073709551615 decimal

Values above 2⁵³−1 use BigInt so you get exact decimal output instead of rounded JavaScript numbers.

Workflow guides

Step-by-step chains that connect related tools for common tasks.

Inspect bit-level representations

  1. Choose Binary, Decimal, Octal, or Hexadecimal as the source base.
  2. Enter numeric tokens separated by spaces or newlines.
  3. Enable Auto-convert or click Convert Now.
  4. Read 8-bit padded binary when you need byte-aligned output.

Share a conversion setup with your team

  1. Set From/To bases, padding, and input tokens.
  2. Click Share to copy a URL with encoded settings.
  3. Teammates open the link to restore the same configuration.

Reference tables

Common radix quick reference

Same value 255 in different bases.

BaseNameExample
2Binary11111111
8Octal377
10Decimal255
16HexadecimalFF

Base Converter at a glance

How this EverydayTools page compares for typical use.

AspectEverydayToolsTypical alternative
BasesBin, dec, oct, hex, text, custom 2–36Often two bases only
Large integersBigInt exact pathRounded doubles
PrivacyBrowser-localCloud upload
ExtrasAuto-convert, share URL, historySingle-field only
CostFreePaid or ads

Best practices

Pad binary when inspecting bytes

Enable 8-bit binary padding so each token aligns to a byte boundary—easier to match hex dumps and packet captures.

Use share links for reproducible debugging

Copy the share URL when filing bugs or PR comments so reviewers see the exact bases, padding, and input you used.

Pick encoding before text↔hex

ASCII and Latin-1 reject out-of-range characters early; UTF-8 handles full Unicode for international strings.

Common mistakes to avoid

Expecting signed two's-complement interpretation

This tool treats values as unsigned integers. For signed 8/16/32-bit layouts, manually apply two's-complement rules or use a dedicated bitwise tool.

Trusting JavaScript Number for 64-bit hex

Values above 2⁵³−1 lose precision with plain Number. Watch for the BigInt banner—output is exact when it appears.

Mixing text and numeric modes

Text mode emits per-character code points. For raw byte buffers, convert numeric byte values with decimal or hex as the source instead.

When this tool isn't the right choice

You need floating-point radix conversion

This tool handles integers and Unicode code points only. IEEE-754 float bit layouts need a dedicated float inspector.

You need signed fixed-width bit fields

Two's-complement signed interpretation is not modeled. Use an embedded calculator or language REPL with explicit bit width.

You need arbitrary-precision decimal fractions

Radix conversion here is integer-only. Rational or decimal fractions require symbolic math tools.

How browser base conversion works

Numeric tokens are parsed digit-by-digit into BigInt, then formatted to the target radix with toString(radix). Text mode maps each character to its Unicode scalar value before formatting. Validation runs before conversion so invalid digits are caught with line numbers.

Formula

value = Σ (digitᵢ × radixⁱ) · output = value.toString(targetRadix)

Limitations

  • Unsigned integers and Unicode scalar values only
  • No signed two's-complement or float bit layouts
  • Share URLs truncate input above ~800 characters
  • File upload limited to small .txt files read locally

How to use Base Converter

  1. Choose source and target bases

    Select Text, Binary, Decimal, Octal, Hexadecimal, or Custom (radix 2–36) for the From side, then pick the To base (e.g. decimal to binary or hex to text).

  2. Enter values or upload a file

    Type numbers separated by spaces or newlines, paste a string for text mode, or upload a small .txt file read locally in your browser.

  3. Convert or enable auto-convert

    Click Convert Now or turn on Auto-convert for live output. Use Ctrl+Enter (⌘+Enter on Mac) as a shortcut.

  4. Copy, share, or download results

    Copy the output panel, copy a share link to restore settings via URL, or download as .txt. Swap direction to reverse the conversion using the latest output.

  5. Restore from recent history

    Click any recent conversion below the tool to reload that input and base pair.

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Frequently Asked Questions

How do I convert binary to hexadecimal?

Group binary bits in fours from the right (pad left with zeros), map each nibble to one hex digit, or paste binary tokens here and select Hexadecimal as the output base. Example: 01001000 → 48 hex.

How do I convert decimal to binary?

Enter decimal tokens (e.g. 65 66 67) with Decimal as the source and Binary as the target. Enable 8-bit padding in the output view to align byte boundaries.

Does it support negative numbers?

The converter targets non-negative integers and text code points. Signed two's-complement layouts are not modeled—use it for unsigned bit-field inspection.

Why does binary output pad to 8 bits?

Padding makes byte-sized values easier to scan and aligns columns when debugging buffers or network packets.

Can I convert text to hex (ASCII)?

Yes—choose Text as the source, Hexadecimal as the target, and pick ASCII, UTF-8, or Latin-1 encoding. Each character becomes its code point in the selected base.

Is data uploaded when I use Base Converter?

No. Conversions and file reads run entirely in your browser; content is not uploaded to EverydayTools servers for normal use.

Does it support custom bases (e.g. base 12 or base 36)?

Yes. Choose Custom on the From or To side and set any radix from 2 to 36. Digits use 0–9 and A–Z, matching JavaScript parseInt behavior for numeral systems.

What happens with very large integers?

Integers beyond JavaScript's Number.MAX_SAFE_INTEGER (9,007,199,254,740,991) are converted with BigInt for exact results. A banner appears when BigInt mode is active.

Is Base Converter free?

Yes. It is free, requires no signup, and works in modern desktop and mobile browsers.

Privacy, accuracy, and trust

Privacy

Base Converter keeps typical inputs on your device—nothing is uploaded to EverydayTools servers for core calculations.

Accuracy

Standard bases 2–36 use positional notation with BigInt for values beyond JavaScript's safe integer. Text mode uses Unicode scalar values, not UTF-8 byte sequences, unless you interpret bytes as decimal/hex tokens.

How this tool works

Conversion, history, autosave, and share-link encoding run client-side. Recent history is stored in localStorage on this device only.

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Reviewed by EverydayTools Editorial Team on 2026-06-02.