Convert Text to Hex

Yes. The tool iterates Unicode codepoints (using for…of) so surrogate pairs for high codepoints stay together. 😀 (U+1F600) encodes as the 4-byte UTF-8 sequence F0 9F 98 80, shown as one row in the grid. Older converters use charCodeAt which returns UTF-16 code units and produces wrong hex for anything above U+007F.

Yes – click Swap. The reverse parser is lenient about input formatting: 48 65 6C 6C 6F, 0x48 0x65 0x6C 0x6C 0x6F, 48,65,6C,6C,6F, and 48656C6C6F all decode to Hello. Odd-digit input gives “Hex must have even digit count”; non-hex characters give “Invalid hex digit ‘X’ at position N”.

The decoder uses {fatal: true} mode, which throws when bytes don’t form valid UTF-8 – for example a lone continuation byte 80 with no lead byte, or an overlong encoding. Non-strict decoders silently substitute the U+FFFD replacement character ("�") and hide the problem. Strict mode surfaces data corruption instead.

Match your destination. Hex dumps: space. CSV imports: comma. Raw byte strings: continuous (no separator). C/C++/Rust source literals: 0x-prefixed, paste straight as {0x48, 0x65, 0x6C, 0x6C, 0x6F}. The underlying bytes are identical; only display differs.

Mathematically no – 4F and 4f are the same byte (79). The choice is stylistic. Unix tools (od, xxd) default to lowercase. Windows hex editors and macOS Hex Fiend default to uppercase. C/Rust source typically uses lowercase. Pick whichever your codebase uses.

200,000 characters. Beyond that the per-character grid renders too slowly (each row is a DOM node). Hit the cap and you get a specific error message. The grid itself caps at 256 displayed rows with a “… N more” note, but conversion still processes the full input.

The Char column substitutes visible glyphs so rows aren’t blank: space → · (middle dot), newline → ↵, tab → →. The actual encoded bytes (20, 0A, 09) appear correctly in the Hex and Binary columns. Useful when auditing what’s actually in your text.

Functionally they’re equivalent – both convert text to UTF-8 hex and back with per-character analysis. They exist as separate URLs because “string” and “text” are different SEO keywords people search for, even though they mean the same thing in this context.

No. All UTF-8 encoding, hex formatting, decoding, and TSV emission run in your browser using TextEncoder/TextDecoder. Open DevTools → Network and confirm zero requests – even when you Convert or Download. Safe for sensitive text, credentials, or anything you’d rather not send to a third-party converter.

Yes. Total bundle is about 18 KB. Load once, disconnect, keep using. Pure local computation – no fonts to fetch, no analytics, no API. Useful for offline debugging, airgapped environments, or when you don’t trust the network you’re on.