ChatGPT Guide 2026: Plans, Limits, Files, Errors, and Models in One Place
Updated: November 1, 2026
ChatGPT questions fall into a handful of groups: what each plan costs and what the free tier allows, which models are available and how much context they hold, how file uploads and PDFs behave, and what the common error messages mean. Data Studios covers each of these in a dedicated guide, and this page lists them by the question they answer.
Each guide is checked against OpenAI's official pricing pages, help center articles and release notes when it is updated, and this index changes when guides are merged or rewritten, so the links below always point to the current version of each guide.
··········
CHATGPT PLANS, PRICES AND FREE ACCESS.
The plan guides cover the paid tiers from Go to Enterprise, the free plan and its limits, trial offers, cancellation and the choice between a subscription and the API.
........
Guide | What it answers |
What Free, Go, Plus, Pro, Business and Enterprise cost | |
Features and limits of each plan side by side | |
What the free plan includes today | |
Whether a Plus or Pro trial exists and how to verify an offer | |
Limits, availability and how Go differs from Plus | |
When a flat subscription costs less than pay-per-token | |
Cancelling on the web, iPhone and Android, and refunds |
........
··········
CHATGPT MODELS, CONTEXT WINDOW AND MEMORY.
These guides explain which models the model picker offers, which older models were retired, how much text a conversation can hold and what ChatGPT remembers between chats.
........
Guide | What it answers |
The current model lineup and how to choose | |
GPT-4o, GPT-4.1, o3 and other retired models, and what replaced them | |
Token limits, long chats and model differences | |
Whether ChatGPT remembers past chats and how to delete memory | |
How many Deep Research sessions each plan gets |
........
··········
CHATGPT FILES, PDFS AND UPLOADS.
File handling has several separate limits, and the guides below cover each of them, from upload size to the expired-file error.
........
Guide | What it answers |
File size, token caps and plan differences | |
What works with PDFs and where scans and charts fail | |
Which file types ChatGPT can create | |
Why uploads expire and how to fix it |
........
··········
CHATGPT ERROR MESSAGES AND FIXES.
The most searched ChatGPT errors each have their own guide with causes and fixes.
........
Guide | What it answers |
What the message means and how to resolve it | |
App quotas compared with API rate limits | |
VPNs, shared networks and how to clear the block |
........
··········
CHATGPT PRIVACY AND DATA RETENTION.
Two guides cover what to keep out of a chat and what OpenAI stores.
........
Guide | What it answers |
What not to share and which settings help | |
What OpenAI keeps and the controls available |
........
··········
CHATGPT COMPARED WITH GEMINI, CLAUDE, GROK AND COPILOT.
The comparison guides put ChatGPT next to the other main assistants on models, pricing, files and daily use.
........
Guide | What it answers |
Features, pricing and workflows of the three assistants | |
Models, search, files and pricing compared | |
Models, pricing and context of five assistants |
........
··········
THE CHATGPT NAME AND ITS ORIGIN.
What GPT stands for explains Generative Pre-trained Transformer and the technology behind the name, and why it is called ChatGPT covers the last-minute change from "Chat with GPT-3.5" before launch.
··········
FOLLOW US FOR MORE.
·····
DATA STUDIOS
·····
datastudios.org
