Claude vs ChatGPT

The decision

Claude and ChatGPT are both general-purpose choices. The useful comparison is not “which one is smarter.” It is which product surface, model controls, and prompting style fit the job.

Consider Claude when the work leans toward long reading, careful writing, code review, or nuanced synthesis. Consider ChatGPT when the workflow benefits from OpenAI’s model and tool ecosystem, structured output, coding surfaces, or fast movement between chat, files, and API-shaped work.

Prompting differences

Anthropic’s prompting docs explicitly recommend XML tags for complex prompts, so Claude prompts often benefit from labeled sections like <instructions>, <document>, and <examples>. The XML tags in prompts concept explains when that structure helps and when it is just decoration.

ChatGPT prompts benefit from separating task instructions from platform controls. Model choice, reasoning effort, tools, and structured-output mode belong in the ChatGPT product or API settings when those controls exist.

Prompt examples

Claude-style long-context prompt:

<instructions>
Review this migration plan for blocking risks. Cite the section behind each concern.
</instructions>

<plan>
{{plan}}
</plan>

ChatGPT-style API brief:

Extract risks from this plan. Return JSON fields for severity, risk, evidence, and
recommended_next_action. Use null for missing evidence.

What to avoid

• Picking one model as a permanent default for every job.
• Copying Claude XML-heavy prompts into a short ChatGPT task when plain text is clearer.
• Pasting API control names into a GUI chat box as if they change settings.
• Comparing answers without matching context, files, tools, and model strength.