Split a long text for AI
The report, the contract or the transcript will not fit in one message, and the chat truncates it or refuses. Here the text is split into numbered parts cut where a paragraph or a sentence ends, with the «part 1 of 7, do not answer yet» line ready: you copy and paste, one after another. The text never leaves your browser.
Why cutting by eye does not work
Pasting a long text in pieces is what everybody does, and it is nearly always done badly: the cut falls in the middle of a sentence (and the model understands half of it), or a line goes missing on the way, or the same paragraph gets pasted twice unnoticed. Here the cut always looks for the best place, in this order: the end of a paragraph, then the end of a line, then the end of a sentence, then the space between two words. It only cuts inside a word if that word alone is longer than the limit, and then it says so.
The guarantee: put back together it is identical
This is what makes this tool different from cutting every so many characters: the parts, joined one after another, give exactly the text you started from, character by character, spaces and line breaks included. Nothing is removed and nothing is added. Under the parts there is a line confirming it every time, and the same thing is checked on thousands of random texts whenever the program changes.
The service line, and why it counts towards the limit
If you paste a part and nothing else, the model answers straight away and starts commenting on half a document. The line in front («part 1 of 7, do not answer yet») is there for that, and the last one says it can start. What nobody thinks about is that that line takes up room in the message too: here it is counted inside the limit, and since the wording gets longer once there are ten parts, the sum is done again. If you prefer your own wording, change it: {n} and {t} become the part number and the total.
How many characters per part
It depends on the chat you use, and the numbers change often: the buttons above are sizes that work nearly always. If the model complains or truncates the answer, go lower; if it asks you to continue, you are already inside. One piece of advice worth more than any number: smaller parts work better than parts at the limit, because it leaves the model room to answer. And remember that the message limit is not the conversation limit: after many parts, the first ones can fall out of the chat's memory.
What it does not do
It does not summarise and does not change a comma: it only cuts. If the text comes from a PDF with broken lines, it is worth putting it back together first with Fix text copied from a PDF; to pull it out of a document there are Extract text from PDF and Open a .docx file. And if the text holds names, addresses or numbers you would rather not feed to a chat, first go through Anonymise a text.