Short recommendation
If your top priorities are low hallucination and careful, long-context legal analysis, start with Claude (better out-of-the-box for sustained, cautious reasoning). If you need broad integrations, plug-ins, or you already have a ChatGPT workflow, ChatGPT is a solid alternative. Either way, don’t rely on the model alone for citation verification — use a strict retrieval + human-check workflow.

Decision criteria (pick what matters most)
- Accuracy / low hallucination: Claude > ChatGPT by default in careful-analysis tasks, but only when paired with verified sources.
- Context length (multi-page memos): Claude has an edge for long-context stability. ChatGPT (latest GPT) also works if you chunk and stitch carefully.
- Ecosystem & integrations: ChatGPT if you need many plugins or automation hooks. Claude if you prioritize analytical safety.
- Budget & skill: ChatGPT has cheaper tiers and more community prompts; Claude may cost more for long-context sessions. Team size matters — larger teams should standardize verification steps.

Prompt strategy (practical template + rules)
- Use retrieval-augmented generation (RAG): feed only verified statutes/cases/authorities as context. Don’t ask the model to “search” the web by itself unless you’ve validated its sources.
- System/instruction example: “You are a legal drafting assistant. Use only the attached sources. For every statement of law, provide a pinpoint citation (page/paragraph or reporter citation). If the sources don’t support a statement, write ‘INSUFFICIENT SUPPORT’.”
- Chunking: split very long memos into sections (issue, rule, analysis, conclusion). Generate each section, then ask the model to synthesize with citations preserved.
- Ask explicitly for provenance: “For each sentence that asserts law or fact, attach the exact citation and the quoted text (<=50 words) it comes from.”
- Ask for a confidence tag per citation (e.g., High/Medium/Low) and explanation for any uncertainty.

Verification steps (non-negotiable)
1. Cross-check each model-provided citation against primary sources (official reporters, statutes.gov, court websites, Westlaw/Lexis). Never accept a citation without opening it.
2. Use a citation parser or Bluebook tool to confirm correct formatting and pinpoint pages/paragraphs.
3. Spot-check factual quotations against the original text to avoid misquotes.
4. Have a lawyer reviewer sign-off on legal conclusions and cite reliability.

Best-for / Avoid-if
- Best for Claude: long analytical memos where you can feed exhaustive context and want careful stepwise reasoning.
- Best for ChatGPT: workflows needing connectors, templates, or cheaper rapid drafting with stronger tooling.
- Avoid either: using the model as a primary legal researcher without RAG and human verification.

Practical checklist before finalizing a memo
- Gather primary authorities and feed them as context.
- Use a strict prompt template that requires exact citations and quoted snippets.
- Chunk and synthesize; request confidence labels.
- Cross-check every citation in primary sources.
- Lawyer review and redline for substance and style.

Bottom line: Claude is the better starting point for precision and long memos; ChatGPT is fine if you need integrations. The deciding factors are your verification workflow, budget, and how much human legal review you require. If you want, I can draft a concrete prompt template and a short checklist you can paste into your workflow.

Compare Claude and ChatGPT