Is Claude or ChatGPT better for small business?

On our five October 2026 tests, GPT-6.1 Sol scored higher than Claude Opus on inbox triage, receipts and finance, they tied at 100% on scheduling, and Claude Opus led customer support replies at 98.6.

Which is better for customer service emails?

Claude Opus scored 98.6 and GPT-6.1 Sol 97.3. Both ran two passes with no severe errors. GPT-5.4 mini scored 68.0 and leaked another customer's data on 2 emails.

Did you test the ChatGPT and Claude apps?

No. We tested the models themselves, not the apps, their plans, or features like file uploads and connectors.

Which cheaper model is safer?

GPT-6 Luna, a low-cost model, had the top finance score at 96.3. Claude Haiku filed scam emails as Act in our inbox test and made 6 severe errors on support replies.

RealRun / Guides

Claude vs ChatGPT for small business (2026)

Short answer: It depends on the job, and on which model you pick inside each brand. Head to head, OpenAI's GPT-6.1 Sol beat Claude Opus on three jobs: inbox triage (GPT-6.1 Sol 95.0%, Claude Opus 94.4%), receipts (GPT-6.1 Sol 95.8, Claude Opus 89.7) and finance (GPT-6.1 Sol 96.0, Claude Opus 93.2). They tied at 100% on scheduling. Claude Opus led customer support replies at 98.6. The bigger gap was inside each family: Claude Haiku filed scam emails as Act, and GPT-5.4 mini came last on support.

Scores by job

Model	Inbox triage	Scheduling	Receipts	Finance	Support replies
GPT-6.1 Sol	95.0	100.0	95.8	96.0	97.3
GPT-6 Luna	not tested	not tested	91.4	96.3	82.2
GPT-5.4 mini	95.0	90.0	not tested	not tested	68.0
Claude Opus	94.4	100.0	89.7	93.2	98.6
Claude Sonnet	91.7	100.0	not tested	not tested	89.4
Claude Haiku	85.6	96.7	92.8	91.7	80.5

Inbox triage and scheduling are percentages; receipts, finance and support are 0 to 100 scores with points off for severe errors. ChatGPT runs on OpenAI's GPT models, so we tested the GPT models directly. We did not test the ChatGPT or Claude apps, their plans, or features like file uploads and connectors.

How the testing works: we wrote our own synthetic test sets with planted traps, like scam emails, calendar conflicts, bad math and fake invoices. Each job also has a separate held-back set, written blind and kept out of all prompt and scoring tuning, that only ran at the end. Every model in a job got the same items. Most ran 2 or more passes; in the support test 3 of 10 models ran 1 pass and are marked less certain. All data is synthetic, never real accounts. Scores differ by job (accuracy %, valid-answer % or a 0 to 100 score with 5 points off per severe error), so compare models within a column, not across columns.

Results updated 15 Oct 2026. Tests run October 2026. Full data: results.json.

Pick by job

Email: GPT-6.1 Sol or the low-cost GPT-5.4 mini (95.0%). Skip Claude Haiku, which filed scam emails as Act.
Scheduling: GPT-6.1 Sol, Claude Opus and Claude Sonnet all scored 100% on fresh requests.
Receipts: GPT-6.1 Sol (95.8, no severe errors) or GPT-6 Luna on a budget. Claude Opus had severe errors in both passes.
Finance: GPT-6 Luna (96.3) was the cheapest of the near tie at the top. Claude Opus (93.2) and Claude Haiku had no severe errors either.
Customer support: Claude Opus (98.6) or GPT-6.1 Sol (97.3), both two passes with no severe errors. Avoid GPT-5.4 mini.

For you

The way this goes wrong is picking a brand instead of a model. GPT-5.4 mini scored 95.0% on email but 68.0 on support replies. Claude Opus filed no scams as Act while Claude Haiku did. Whichever app you pay for, check which model it is running before you hand it your inbox or your customer email.

For your clients

When a client asks "Claude or ChatGPT?", answer with the job and the model name, and show the score. You might put Claude Opus on their support inbox and GPT-6 Luna on their bank exports. That is a better answer than picking a side, and you can defend it.

Want the exact prompt and setup?

Get all five playbooks for $99 (save $46).

Get the free weekly AI test report

FAQ

Is Claude or ChatGPT better for small business?: On our five October 2026 tests, GPT-6.1 Sol scored higher than Claude Opus on inbox triage, receipts and finance, they tied at 100% on scheduling, and Claude Opus led customer support replies at 98.6.
Which is better for customer service emails?: Claude Opus scored 98.6 and GPT-6.1 Sol 97.3. Both ran two passes with no severe errors. GPT-5.4 mini scored 68.0 and leaked another customer's data on 2 emails.
Did you test the ChatGPT and Claude apps?: No. We tested the models themselves, not the apps, their plans, or features like file uploads and connectors.
Which cheaper model is safer?: GPT-6 Luna, a low-cost model, had the top finance score at 96.3. Claude Haiku filed scam emails as Act in our inbox test and made 6 severe errors on support replies.

More from RealRun

Scores reflect our tests on the dates shown, not a guarantee. Claude models ran on a Claude subscription, so they have no metered API cost. cost_tier is relative within a task (low/medium/high) from our run spend; 'subscription' = not metered. Tested October 2026 by RealRun (Base Ledger IP LLC).