There is no answer to “Which AI is best?” that is independent of your workflow. A good writing assistant can be awkward when all your information is elsewhere. The most powerful model may be unnecessary for a daily summary.
Today's tools overlap considerably: they handle text and files and offer different ways to continue working. ChatGPT's pricing page describes Work and Codex; Claude lists document, slide and coding tools; Google connects Gemini with its apps. Exact access depends on the plan. ChatGPT, Claude, Gemini.
Compare them using your own material
Choose three tasks: a customer email, a document summary and a report or piece of content. Use material you are allowed to share with every platform in the test. Keep the brief and evaluation criteria the same.
Ask four questions about each result. Are the facts correct? Does the language sound natural? How much editing was needed? How easily did the output reach the place where it will be used?
Record the time in minutes. If one tool writes better but requires ten rounds of copying each time, another may be a better overall fit. Consider the user's experience too: can they change the result themselves or do they need help at every step?
Give a difficult task a second attempt
One poor answer doesn't reveal a tool's full ability. Clarify the brief once and try again. But don't spend hours rescuing something that another tool handles easily.
After choosing, use your main tool consistently for a while. Repeated experience will reveal the limits better than constantly switching platforms. AILithe helps you build a small, practical comparison and choose what fits your team's work.