Hex Tools

Hex tools cover the gaps between hexadecimal and every other base a programmer meets on a given day: decoding a Base64 payload to read the raw bytes, turning a Bitcoin address from Base58 into hex for verification, reading a BCD clock register off an embedded datasheet, or adding two 32-bit values by hand when a debugger is not yet attached. Eight browser-based utilities, all client-side, all free. For the wider context on converting between numeric bases, see the binary and encoding tools.
What you can do with hex tools

Convert any common encoding into hexadecimal: ASCII, binary, Base32, Base58, Base64, and BCD.
Do arithmetic and bitwise work directly in hex without switching back to decimal: add hex numbers for sums, AND hex numbers for bitmask operations.
Inspect memory dumps, network captures, or crypto payloads by moving between whatever encoding the upstream system produced (Base58 from wallets, Base64 from APIs, BCD from industrial sensors) and the byte-level hex view.

Reach for hex when the underlying data is binary and you want a compact, unambiguous, human-readable form: two characters per byte, case-insensitive, one digit per nibble. If the job is a conversion between two non-hex bases (Base32 to Base64, binary to octal), the binary and encoding category has the cross-base converters. If the task is arithmetic in decimal or flipping integer signs, the number category is closer.
The Hex toolkit

Tool
What it does
When to use

Add Hex Numbers
Adds two hexadecimal values and returns the sum in hex, decimal, and binary.
Summing 0x7F and 0xA3 while reading assembly output, without flipping to the calculator app.

Hex AND Calculator
Performs bitwise AND between two hex operands.
Masking a 32-bit status register, for example 0xFFFF & 0x00F0 to isolate four specific bits.

ASCII to Hex
Encodes an ASCII string into hex byte values, one pair per character.
Preparing a test payload: turning SELECT into 53454C454354 for a SQL injection fuzzer input.

Base32 to Hex
Decodes Base32 (RFC 4648) into raw hex bytes.
Inspecting a TOTP secret or a Google Authenticator backup QR code that exported as Base32.

Base58 to Hex
Decodes Bitcoin-style Base58 into the underlying hex bytes.
Verifying that a Bitcoin or Solana address matches its public key hash during a wallet audit.

Base64 to Hex
Decodes a Base64 string into its hex byte sequence.
Reading the actual bytes of a JWT signature or an API response before running it through a decoder.

BCD to Hex
Converts Binary-Coded Decimal packed bytes into plain hex.
Interpreting date and time registers on an RTC chip like the DS1307, or reading sensor data from a legacy industrial protocol.

Binary to Hex
Groups a binary string into 4-bit nibbles and outputs hex.
Turning 11010010 from a protocol spec sheet into 0xD2 without counting bits manually.

How to choose the right hex tool

If the input is printable text (letters, digits, punctuation), use ASCII to Hex. Each character becomes a two-digit hex pair.
If the input is a raw encoded blob from a web API, JWT, or SSL certificate, start with Base64 to Hex. Base64 is the default format for binary-over-text on the web.
If the input looks like a wallet address or OAuth-style token, pick Base32 to Hex or Base58 to Hex. Base32 uses uppercase letters and digits 2 to 7. Base58 omits the visually ambiguous characters 0, O, I, and l.
If the input is a string of 0 and 1 from a datasheet or protocol trace, go to Binary to Hex.
If the input comes from clock, date, or status registers on embedded hardware, that is usually BCD. Use BCD to Hex.
For arithmetic, add with Add Hex Numbers and mask with Hex AND.

Rule of thumb: you are probably reaching for hex because some other representation became inconvenient. Start with the tool whose input matches whatever the upstream system produced.
Frequently asked questions
Q: Why use hex instead of decimal?
One hex digit encodes four bits, two digits encode a byte. Memory dumps, MAC addresses, cryptographic hashes, opcodes, and CSS colors are byte-oriented, so hex keeps the bit structure visible and cuts character count against decimal. 0xFF and 11111111 show the same structure; 255 hides it.
Q: Is hex case-sensitive?
No. 0xAB and 0xab are the same value. Output defaults to uppercase for traditional hex-dump style, but Rust, Go, and most REST APIs favor lowercase.
Q: What does the 0x prefix mean?
It tells the reader “hex, not decimal.” C, Python, and JavaScript require it at the language level. The tools accept input with or without it; output is always prefixed for clarity.
Q: What is BCD?
Binary-Coded Decimal packs each decimal digit as a 4-bit group, so 25 becomes 0010 0101, not the pure binary 00011001. RTC chips (DS1307, DS3231) and some industrial protocols use it. Standard binary-to-hex gives the wrong number; BCD to Hex reads each nibble as a decimal digit first.
Q: How is Base58 different from Base64?
Base58 drops the visually ambiguous characters 0, O, I, l, plus the + and / that Base64 uses (both break URLs and shell commands). The 58-character alphabet is safe for printing wallet addresses by hand; Bitcoin and Solana use Base58Check.
Q: Are my inputs sent to a server?
No. All eight tools run client-side in JavaScript. The browser network tab confirms no request leaves the page.
Related categories
Hex sits between a few neighboring toolkits. The binary and encoding category holds every Base N cross-converter that does not end in hex (Base32 to Base64, octal to decimal). The number category handles decimal arithmetic, integer sign flips, and base-conversion work beyond hex. For developer utilities built on hex values (hash generators, token encoders, URL encoders), start in the developer category.