Blog · AI & Outreach
June 27, 2025 · 5 min read
The question of which AI model to use for outbound copy comes up constantly, and the answer depends more on how you use the model than on which model you choose. That said, GPT and Claude — the two most widely used models in sales workflows — have meaningful differences that affect the quality of their output for specific copywriting tasks.
The comparison below is based on practical use cases: writing cold email first lines, generating follow-up variations, editing drafts, and producing subject line options. Both models were given the same prompts with the same input data.
GPT is faster at structured extraction and variation generation. Given a company description and a list of product benefits, it quickly produces multiple email variations with different angles — useful when you want to test different framings without spending time writing each manually. The output is reliably grammatical and professional.
GPT also has the broader ecosystem advantage. More tools are built on the OpenAI API, which means more integrations, more Clay tables using GPT, and more documentation for prompting strategies. If your team is not using AI directly but through embedded tools, there is a good chance GPT is already doing the work.
Claude produces more natural-sounding cold email copy. The writing tends to be less formulaic and less obviously AI-generated — a meaningful advantage in an era when experienced buyers have developed a feel for AI text. Given a specific research brief about a prospect, Claude is more likely to produce a first line that sounds like it was written by a person who actually read about the company.
Claude also handles nuance better in editing tasks. If you give it a draft and ask it to make it feel less salesy without losing the key message, the output tends to be more useful than GPT's equivalent. For the final-mile editing that separates acceptable copy from good copy, Claude's output requires less rework.
Both models are capable tools and neither is dramatically better than the other for outbound copy. The gap between a good prompt and a bad prompt is far larger than the gap between the two models. A mediocre prompt given to the better model will produce worse output than a good prompt given to the worse model.
If you are choosing one: use Claude for first-line personalisation and editing tasks where tone matters. Use GPT for structured extraction, variation generation, and workflows inside tools that already use the OpenAI API. For most teams, the model choice matters less than developing good prompts and reviewing the output before it reaches a prospect.