Pasting long text into AI chats

When a document won't fit in the message box, split it into numbered parts and send them in order — here's the reliable way to do it.

The problem

ChatGPT, Claude, Gemini and other AI assistants all cap how much you can put in one message. The exact limit varies by service, plan and model — and changes without notice — but the symptom is always the same: your paste gets cut off, rejected or silently truncated, and the AI answers based on half the text.

The fix: numbered parts with a "wait" instruction

Split the document into parts and send them one after another. Two details make this work well:

Number the parts so nothing is lost or reordered.
Tell the AI to wait until all parts have arrived before answering.

SplitMyText does both automatically. With Number Each Part switched on, every part starts with a header like [Part 2/5 — wait for all parts before replying], so the model holds its answer until you've pasted the last one.

How to do it

Open the splitter and paste your full text.
Set a part size comfortably under the chat's limit — if you don't know it, 8,000 characters is a safe, efficient default for the major assistants.
Turn on Number Each Part and click Split Text.
Use Copy Next to work through the parts in order — it tracks which one you're on.

Why use this tool for it

The text you're pasting into an AI chat is often exactly the text you don't want passing through yet another server. SplitMyText never uploads or stores anything — the splitting happens in your browser, and cuts land on word boundaries so no sentence is chopped mid-word. On a phone, the app does the same from the share sheet.