Hex Decode

100% client-side processing (no server upload). Decode Hex back to readable text with selectable input formats (plain, 0x…, \xHH, %HH), optional separator handling, odd-length rules, and strict validation.

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About Hex Decoder (Text)

Use this page to decode Hex into text directly in your browser. You can accept common Hex notations like plain hex, 0x-prefixed values, C-style \xHH escapes, or percent-encoded %HH bytes, and choose how strict parsing should be. Need the opposite direction? Use the other page.

Features

100% client-side processing (no server upload).
Decode multiple Hex notations: plain, 0x… prefix, C \xHH escapes, and %HH percent encoding
Strict validation toggle to reject malformed input early
Separator handling for spaced or tokenized hex (spaces, colons, dashes, underscores, commas, and whitespace)
Odd-length handling: error out or left-pad with 0 before decoding
Charset selection for bytes → text (unsupported charsets fall back to UTF-8)
Optional line-by-line processing and selectable output line endings (LF or CRLF)

How to use for hex-decoder

Paste or drop your Hex

Paste your hex input into the editor (you can also drop text files like .txt, .log, .md, .json). If your input contains 0x… prefixes, \xHH tokens, or %HH sequences, keep the matching "Accept" options enabled.

Click "Decode"

Select the expected input notation (plain / 0x / C escape / percent), choose whether to allow separators/whitespace, and decide how to handle odd numbers of hex digits. Turn on "Strict validation" if you want failures instead of best-effort parsing.

Copy or download the result

Review the decoded text output. Copy it to your clipboard or download it as a text file. If characters look wrong, try a different "Character set" for bytes → text.

Technical specifications

Execution Model

This page performs Hex decoding in your browser and does not upload your input to a server.

Aspect	Detail
Runtime	100% client-side processing (no server upload).
Variant scope	Decode page (Hex → text)
Limits	~1–2MB chars; ~25000 ms timeout
Retention	All processing happens locally in your browser (no upload)
Input	Text (hex digits with optional prefixes/tokens and separators)
Output	Text (bytes decoded then interpreted using the selected character set)

Even with local processing, avoid pasting secrets you can't afford to expose (screen sharing, browser extensions, telemetry, and copy/paste history can still leak data). Prefer local CLI decoding for sensitive material.

Mini Example

A minimal decode example using plain hex.

Input (plain hex): 48656c6c6f0a
Output (UTF-8): Hello

If your input uses tokens like "0x48 0x65" or "\x48\x65", enable the corresponding "Accept" options and allow separators if needed.

Errors & Edge Cases

Common decoding failures and the options that affect them.

Symptom	Likely cause	What to check
Invalid hex characters	Input contains non-hex characters (or malformed prefixes/tokens)	Enable/disable "Ignore non-hex characters" and "Strict validation"; verify you selected the right format
Odd number of hex digits	Truncated input or missing a nibble	Set "Odd hex digits" to "Left-pad with 0" or keep "Error" to fail fast
Nothing decodes / empty output	All characters were filtered out (lenient mode) or tokens weren't recognized	If you expect tokenized input, enable "Accept 0x prefix" / "Accept \xHH escapes" / "Accept %HH encoding" and "Allow separators/whitespace"
Garbled characters (mojibake)	Decoded bytes interpreted with the wrong charset	Change "Character set" (unsupported charsets fall back to UTF-8)
Different outputs per line	Line-by-line mode changes how text is split and recombined	Disable "Process line by line" if you need a single continuous decode

Command line alternatives

For secrets, automation, or reproducible pipelines, decode locally. Below are common, canonical options for Hex → bytes/text.

Linux/macOS

Decode plain hex to bytes (xxd)

printf %s "48656c6c6f0a" | xxd -r -p

xxd "reverse" mode converts a plain hex stream into raw bytes. Pipe to a viewer (cat) or a file redirect if needed.

Decode hex to UTF-8 text (Python)

python -c "import binascii; s='48656c6c6f0a'; print(binascii.unhexlify(s).decode('utf-8'))"

Unhexlify produces bytes; decode them with the correct charset (UTF-8 shown).

Node.js

Decode hex to UTF-8 text (Node Buffer)

node -e "const hex='48656c6c6f0a'; console.log(Buffer.from(hex,'hex').toString('utf8'));"

Buffer.from(hex, 'hex') parses plain hex (no 0x / C-style escapes). Strip prefixes/separators first if present.

Windows PowerShell

Decode plain hex to bytes and print as UTF-8

powershell -NoProfile -Command "$hex='48656c6c6f0a'; $bytes=for($i=0;$i -lt $hex.Length;$i+=2){ [Convert]::ToByte($hex.Substring($i,2),16) }; [Text.Encoding]::UTF8.GetString($bytes)"

Build a byte array from hex pairs, then decode bytes using UTF-8.

Use cases

Inspect encoded payloads

Turn a hex dump back into readable text during debugging
Quickly validate that a copied hex value actually represents the expected string

Pipeline troubleshooting

Decode hex fields from logs or messages to verify upstream transformations
Normalize inputs that mix separators or token styles before deeper analysis

CI sanity checks

Verify fixtures where test vectors are stored as hex strings
Fail fast with strict validation to catch malformed data early

Teaching bytes vs text

Demonstrate how bytes map to characters depending on charset choice
Show why odd-length hex or invalid digits must be handled explicitly

❓ Frequently Asked Questions

Is there a public API?

No. This tool is designed for interactive browser use and does not expose a public API.

Is processing local or remote?

100% client-side processing (no server upload). All decoding runs locally in your browser.

Can I paste secrets (API keys, passwords, tokens)?

It's safer not to. Even though decoding is local, secrets can still leak via screen sharing, browser extensions, clipboard history, or device compromise. For sensitive data, prefer local CLI decoding.

Why do I get a validation error or "invalid hex"?

Most failures come from non-hex characters, malformed prefixes/tokens, or an odd number of hex digits. Check the selected Hex format, enable the matching "Accept" toggles (0x / \xHH / %HH), and decide whether to allow separators and/or ignore non-hex characters. If you need strict parsing, enable "Strict validation" and disable "Ignore non-hex characters".

The decoded text looks corrupted. What should I do?

That usually means the bytes were interpreted with the wrong character set. Try changing "Character set" (for example UTF-8 vs ISO-8859-1). Unsupported charsets fall back to UTF-8.

Pro Tips

Best Practice

If you expect inputs like "0x48 0x65" or "\x48\x65", keep the matching "Accept" toggles enabled and allow separators/whitespace.

Security Tip

Use "Strict validation" + disable "Ignore non-hex characters" when you want decoding to fail fast instead of silently skipping junk.