Compare Comet and ChatGPT on through-train fares
Ole Reissmann asked ChatGPT Agent and Perplexity Comet, in German, to find and book the cheapest train from Hamburg to Copenhagen for a September trip. He used the same practical objective to compare price and browser execution.
olereissmann.com
Suggested prompt
Suggested prompt written by Agents In Use, not the source author. Replace bracketed inputs and review tool permissions first.
Find the cheapest Hamburg-to-Copenhagen train for these dates. Compare through fares with separate-leg tickets, record the full journey total, and show the booking details before purchase.
Reach people exploring AI agents
See placements →Evidence at a glance
Sourced account- Source author
- Ole Reissmann
- Original account
- Read the source ↗
- Published
- Source link checked
- Reported result
- ChatGPT found €63.26 versus Comet's €70.94 for the same connection; Comet's separate-ticket approach missed the lower through fare.
- Human involvement
- ChatGPT asked Reissmann to sign in; the account provides no payment receipt or ticket confirmation.
A linked account supports attribution. It does not mean we independently reproduced its result.
Report an issue with this case
Open correction emailOpens your email app with the case link included. Nothing is sent automatically.
How the agent did it
- Specify the complete journey and cheapest-fare objective.
- Compare complete-connection prices against separate train tickets.
- Record total price, ticket structure and any login handoff.
Ole Reissmann asked ChatGPT Agent and Perplexity Comet, in German, to find and book the cheapest train from Hamburg to Copenhagen for a September trip. He used the same practical objective to compare price and browser execution.
ChatGPT Agent found a fare of €63.26. Reissmann watched it work through cookie banners and journey options before it asked him to sign in through its browser. He reports that the sequence took ten minutes and felt considerably slower than booking manually on Deutsche Bahn.
Comet completed its run in three minutes and forty seconds, but produced a higher total of €70.94. The connection was the same; the difference came from booking the trains separately rather than finding the cheaper combined fare. Speed therefore did not establish that the cheapest option had been identified.
The account provides a concrete distinction to retain when copying the task: compare the total for the complete connection with separate-leg fares, and record the ticket structure alongside the amount. Reissmann describes the booking behavior but does not show a payment receipt or ticket confirmation. The result should be understood as his reported comparison, with the ChatGPT sign-in handoff explicitly documented.
Prompt
Suggested prompt (written by Agents In Use, not the author's)
Source: olereissmann.com · Ole Reissmann
Frequently asked questions
Why did the totals differ?
Comet booked trains separately, while ChatGPT found a cheaper fare for the complete connection.
Which run was faster?
Reissmann reports three minutes forty seconds for Comet and ten minutes for ChatGPT Agent.
Does the article show a ticket receipt?
No. It reports prices and booking behavior, and documents ChatGPT's request for a login.
More details
About this account
Both agents navigated travel sites; Comet completed its reported run faster but selected separate tickets.
Firsthand source opened and read. Suggested prompt written by us from the reported workflow; no original task prompt is quoted.
Credit: Ole Reissmann
Source published
Added to Agents In Use
Source checked
Tools and topics
Perplexity Comet · ChatGPT agent · Deutsche Bahn website
Train fares · Through tickets · Hamburg to Copenhagen
Editorial completeness: 100/100. Measures documented fields, not agent performance or verified outcomes.