Hex/ASCII Converter

Convert hex and ASCII in both directions

Firmware logs, UART dumps, and BLE traces often show bytes as hex. This page turns that hex into readable ASCII, and the other way around, without a script.

1. 1. Hex to ASCII

   Paste hex with or without spaces. Pairs of characters become bytes, then characters. Invalid hex is reported instead of guessed.

2. 2. ASCII to hex

   Type or paste the text. Each character becomes a two-digit uppercase hex byte.

3. 3. Copy the side you need

   Use hex when you are writing a buffer; use ASCII when you are reading a log.

Frequently asked questions

Is this the same as UTF-8 decode?

It maps bytes to Latin-1 / char codes. Multi-byte UTF-8 sequences will not round-trip as a single glyph. For MQTT JSON payloads, use the MQTT decoder instead.

Are spaces in hex allowed?

Yes. Spaces are stripped before parsing.

Does any of this upload?

No. Both directions run in the browser.