If you copy and paste from ChatGPT, is there a watermark?

No. Copying text out of ChatGPT doesn't carry a watermark across, because there is no watermark in the text to begin with. What can come across with the paste is the odd invisible Unicode character, and that is a different thing entirely.

Why there's nothing to carry

OpenAI built a text watermarking method and, by its own account, decided not to release it. It has never announced shipping one since, so ChatGPT doesn't leave a watermark in what it writes — there is nothing in the text to find, and nothing to remove. If you want the longer version of that story, it's in does ChatGPT watermark text?.

That also settles the question people usually ask next. There is no way to find a ChatGPT watermark in pasted text, and a tool advertising that it detects one is hunting for something that was never deployed.

What can actually come across

Stray whitespace characters. The one people hit most is the narrow no-break space, U+202F, sitting where an ordinary space belongs — reported in GPT-4o output and again in GPT-5. Ordinary non-breaking spaces turn up too. They're invisible on screen, they survive copy-paste, and they can make text render strangely once it lands somewhere else.

Two things worth knowing about these ChatGPT hidden characters:

• They aren't an AI signature. Word, InDesign, PDF exports, translation tools and correct French typography all produce the same characters.
• They're inconsistent. They vary between models and don't appear in every response, which is not how a watermark behaves. OpenAI's position is that they're artefacts of training, not a deliberate mark.

Checking a paste before you send it

Paste the text into the hidden character checker. It lists every invisible codepoint it finds and hands the text back clean, which is worth doing before the text goes into a form, a code file or a submission portal that trips over unusual whitespace.

What it won't tell you is whether a model wrote the text. Finding U+202F doesn't show that, and finding nothing doesn't show a person wrote it either.