The MKD blog
Short, sourced guides to the file problems every AI user hits — token costs, context windows, upload limits — and the conversions that fix them. No filler; every number cites its documentation.
Why can't ChatGPT read my PDF?
The four real causes behind the error — scanned pages, protection, size and upload caps — and the fix for each one.
Read →“Claude hit the maximum length for this conversation” — what it means
What the context window actually is, why file uploads fill it so fast, and how to continue the work without losing it.
Read →How many tokens is a PDF?
Real per-page numbers from vendor documentation, a table from 1 to 600 pages, and how to measure your own file.
Read →ChatGPT file upload limits, and the honest workaround
The documented caps — per file, per day, per plan — and why shrinking files beats fighting the limits.
Read →The tool behind the blog
Everything here comes back to one idea: files are expensive for AI chats, text is cheap, and the conversion can happen privately in your own browser. The converter is free and unlimited — PDF, Word, PowerPoint, images, HTML and ZIP.