Let a browser agent compare three options for a trip or purchase, then stop before paying

Steps

1. 1Pick one agent. Comet is Perplexity’s own browser, free to download for Mac and Windows: install it, sign in, and open the Assistant from the sidebar. Claude in Chrome needs a paid Claude plan (Pro or above): add the extension from the Chrome Web Store, click the Claude icon in the toolbar, and set the permission mode to “Manually approve” so it asks before every action. In ChatGPT, the old agent mode is retired; paid plans get a cloud browser inside ChatGPT Work that asks before opening each new site, so start a Work task there if that is what you have.
2. 2Write the job down before you start: what you want (a flight, a hotel, a laptop), hard limits (dates, budget in USD, must-haves), and two or three sites you trust. The prompt below has the placeholders; agents that are told “anywhere on the web” wander and take three times as long.
3. 3Open the sites yourself in separate tabs first, log in if you have an account, and dismiss cookie banners. Then paste the prompt into the agent. In Comet the Assistant uses the page you are on as context and can open the other sites itself; Claude in Chrome works in the tab you are on and asks before moving to another site. ChatGPT’s cloud browser does not share your logins, so it can only read public pages.
4. 4Watch it work and answer its questions. All three agents pause when a site demands a login, a CAPTCHA or a confirmation; type the answer yourself and let it continue. If it heads toward “Buy”, “Book” or a card form, stop it: Deny the action (Claude), close the Assistant pane (Comet) or tell it in the chat to stop (ChatGPT).
5. 5Read the table it returns. Every row must have a direct link to the exact option; open all three links yourself, check that the price, dates and conditions on the page match the table, and make a note of anything that differs (totals change at checkout once fees and taxes appear).
6. 6Ask for one refinement at a time: “swap option 2 for a hotel with free cancellation” or “add a column for total price including taxes”. Keep the same conversation so it remembers the brief.
7. 7Book or buy by hand in the tab you already have open, using your own saved details. Save the final table as a note; next time, paste the prompt again with new dates and the agent repeats the search in a few minutes.

Prompt

Replace anything in { } with your details.

I want to compare, not buy. Find exactly 3 options for: {WHAT YOU WANT, e.g. a round-trip economy flight from {CITY} to {CITY}}.
Hard limits: {DATES OR DATE RANGE}; budget up to {AMOUNT} USD per {person/night/item}; must have: {e.g. free cancellation, carry-on included, 16 GB RAM}.
Search only these sites: {SITE 1}, {SITE 2}, {SITE 3}. Do not open any other site.
Rules:
- Never click Buy, Book, Checkout, Pay or any payment or address form. Stop and ask me if a site requires it to show a price.
- Do not enter my personal details anywhere. If a site asks for a login, pause and tell me.
- Prefer options that meet every must-have; if fewer than 3 qualify, say so instead of relaxing the limits.
Return a table with these columns: option, site, total price in USD (with taxes and fees if shown), key details ({e.g. departure and arrival times, cancellation policy, warranty}), direct link to the exact option, and one line on the trade-off.
Under the table write which option you would pick and why, in 2 sentences. Then stop.

Expected output

A three-row comparison table with total USD prices, key conditions and a direct link per option, plus a two-sentence recommendation; you open the links, confirm the numbers and complete the booking or purchase yourself.

Gotchas

• ⚠ Agents hallucinate prices when a page loads slowly or hides the total behind a click. Treat every number in the table as a claim until you have seen it on the page yourself.
• ⚠ Claude in Chrome blocks purchases and card details in every permission mode by design; Comet and ChatGPT can click further than you expect, so keep the “never click Buy” rule in the prompt and stay at the screen.
• ⚠ Travel and shopping sites show different prices to different sessions and often block automated browsing with CAPTCHAs. Solving them is your job, not the agent’s; if it loops on one site, drop that site from the list.
• ⚠ Everything the agent sees on the page goes to the model provider. Do not run it in a tab where your card or passport details are visible, and log out of banking tabs first.
• ⚠ Comet is free, but Claude in Chrome needs a paid Claude plan and ChatGPT’s cloud browser is only on paid ChatGPT plans in supported regions, with limits that change during rollout.