HARPA AI Alternatives: Browser AI Agents Compared (2026)

TL;DR: The right harpa ai alternative depends on which HARPA job you need. For an AI that clicks through websites, try Claude in Chrome or Gemini in Chrome's auto browse. For a chat sidebar, Sider, Monica, MaxAI or Merlin. For better prompts, a prompt tool. ChatGPT Atlas is no longer an option: OpenAI shut it down on 9 August 2026.

What is HARPA AI, and which job are you replacing?

HARPA AI is a Chrome extension that mixes two things most tools keep separate: an AI chat sidebar and a browser automation engine. Its homepage, checked 17 September 2026, describes a "hybrid Browser Automation/AI engine" and lists page monitors, price-drop alerts, scraping, scheduled commands, and hand-offs to Make.com, Zapier and n8n, alongside summaries, email drafting and a library of ready-made commands.

That mix is why "HARPA alternative" searches go in three directions. Before you pick a replacement, decide which of these you actually use HARPA for:

1. Browser agent work. The AI reads a page, clicks, types and fills forms for you, or runs a task on a schedule.
2. Sidebar chat. Summarize this page, draft a reply, explain this PDF, with several models in one place.
3. Prompt commands. Reusable, parameterized prompts you run again and again.

No single tool below does all three as HARPA does. Most readers only need one, and the best alternative for that one job is usually better at it than HARPA.

For the full breakdown of HARPA itself, see our HARPA AI review. This page is about what to use instead.

What does HARPA cost in September 2026?

HARPA's paid plans start at $12 a month billed annually. The pricing page, checked 17 September 2026, shows:

Megatokens are HARPA's own credit unit for its cloud models; you can top up, bring your own API keys, or connect through your existing ChatGPT, Claude or Gemini web sessions. The billing FAQ is blunt on one point: "We do not offer refunds." HARPA's stated reason is that every paid feature has a demo period so you can decide before buying.

Store numbers, also checked 17 September 2026: the HARPA Chrome listing shows 4.7 from 3.2K ratings, 400,000 users, version 14.4.0, updated June 29, 2026. The HARPA homepage says "Trusted by 500.000 professionals", which is higher than the Chrome figure; the difference may come from other browsers, but the site does not say.

Why do people look for a HARPA AI alternative?

The reasons we see fall into four groups, each backed by something on HARPA's own pages:

• Credits confuse people. Megatokens, web sessions, BYOK and top-ups are four ways to pay for the same message. That flexibility is useful, and also hard to predict.
• No refunds. If you buy the annual plan and it doesn't fit, the policy on the pricing page says you won't get money back.
• The model list lags. HARPA's pricing page lists GPT-5.4, Sonnet 4.6 and Gemini 3.1 Pro. Anthropic now classes Sonnet 4.6 as a legacy model, so if you want the newest Claude, you may get it faster from Anthropic directly.
• First-party agents arrived. Anthropic, Google and OpenAI all now put agent features in or near the browser. For many users, the AI provider's own agent is the simpler path.

Which browser AI agents can replace HARPA's automation?

Claude in Chrome and Gemini in Chrome are the two first-party agents that live in Chrome itself; Perplexity's Comet is a whole browser built around an assistant. None of them replaces HARPA's page monitors or scheduled scraping one for one, so check that gap before you switch.

Claude in Chrome (Anthropic). Anthropic's help article describes it as a browser extension that lets Claude "read, click, and navigate websites alongside you." It is available on all paid Claude plans (Pro, Max, Team and Enterprise), runs in beta in the Chrome side panel, and can also be driven from Claude Cowork and Claude Code. The same article notes it is not supported on other Chromium-based browsers or on mobile devices, and Anthropic publishes a separate admin-controls article for Team and Enterprise plans.

The Claude Code link is the unusual part: Anthropic describes a build-test-verify loop where you build in the terminal and Claude checks the result in the browser, reading console errors and network requests. For developers, that is a genuinely different use from HARPA.

Gemini in Chrome with auto browse (Google). Google's Chrome blog post of 28 January 2026 introduced auto browse, an agent that handles multi-step chores such as comparing hotel and flight costs. Its footnote reads: "Auto browse is currently rolling out in preview in the U.S. for Google AI Pro and Google AI Ultra subscribers". Gemini in Chrome itself was listed for Windows, macOS and Chromebook Plus in the U.S. If you are outside the U.S. or not on a Google AI plan, check availability before planning around it.

Comet (Perplexity). Perplexity's Comet page, checked 17 September 2026, describes a browser with a built-in assistant that can research, email, shop and build, and lists Mac, Windows, iOS and Android. Comet replaces your browser rather than adding an extension, which is a bigger change than swapping HARPA for another add-on. We did not verify Comet's current plan limits on Perplexity's own pages, so check them before you rely on agent tasks.

ChatGPT (OpenAI). With Atlas discontinued, OpenAI's own direction is the ChatGPT desktop app for agentic browser work and a Chrome extension or sidebar for help while browsing, where available. OpenAI notes that availability depends on plan, region, device, browser and workspace settings.

Which AI sidebars replace HARPA's chat features?

If you mostly used HARPA to summarize pages, draft replies and switch between models, a dedicated sidebar is the direct swap. These four are the largest by Chrome users, all checked 17 September 2026:

The store numbers tell you about adoption, not fit. Sider and Monica are an order of magnitude larger than HARPA and update often; Sider's listing was updated two days before we checked. None of the four is built around page monitoring or scheduled scraping, which is the part of HARPA they do not replace.

For detail on each, see our Sider review, Sider vs Monica, Monica vs Merlin, and our roundup of AI sidebar extensions. The head-to-head HARPA AI vs Sider covers the automation-versus-assistance split in depth, and Merlin AI alternatives covers Merlin's side.

Where does Prompt Architects fit, and where doesn't it?

Prompt Architects is not a browser agent, and it would be misleading to rank it against Claude in Chrome or HARPA's automation. It does not click, scrape, monitor pages or run scheduled tasks.

It covers the third HARPA job: prompts. HARPA's homepage advertises over 100 ready-made, page-aware commands. If those commands and HARPA's writing help are what you actually used, Prompt Architects does that job in a different way. It generates and enhances prompts inside ChatGPT, Claude, Gemini and many other AI tools, stores them in a private library you can share with a team, and brings the same tools into Claude Desktop, Claude Code and Cursor through an MCP server. Built-in AI is included on every plan, so you do not manage keys or credits.

The trade-offs, stated plainly. Our Free plan gives you 5 prompt enhancements per day, per our FAQ, but cannot save prompts; saving starts on Pro at $4.99 a month (50 saved prompts) and is unlimited on Advanced at $9.99, at the time of writing. We have no page monitors, no scraping and no scheduling. Our Chrome listing shows 4.8 from 36 ratings and 1,000 users (v1.7.3, updated September 3, 2026), a far smaller install base than any tool above.

A common setup is to pair one agent or sidebar with one prompt tool: the agent does the browsing, the library holds the tested instructions you give it. Other prompt tools worth a look for that role are covered in our AIPRM alternatives, Superpower ChatGPT alternatives and SurePrompts alternatives guides.

What should you test before trusting a browser agent?

Run a one-week trial on real but low-stakes work before you cancel anything. Four checks catch most problems:

Success rate on your own sites. Pick five tasks you do every week, such as pulling prices from a supplier page or filling a timesheet form, and run each three times. An agent that finishes two out of three is a helper you supervise, not one you can leave alone.

Where it stops. Note what happens at a login wall, a captcha, a cookie banner or a pop-up. Good agents pause and ask. Weak ones guess, or loop.

What it costs per task. Agent runs use far more model calls than a chat reply. Watch how quickly a plan's usage limit or credit balance drops over the week, and compare that with HARPA's Megatoken spend for the same jobs.

What it can see. Check which tabs, sites and accounts the agent can reach, and restrict them where the product allows. An agent with access to your email and your bank in the same browser profile is a risk you can avoid by using a separate profile for agent work.

How do you choose the right HARPA AI alternative?

Match the tool to the job you listed at the top:

The row to read twice is the monitoring one. HARPA's scheduled commands and page monitors are its most distinctive feature, and none of the agents or sidebars above advertise a direct equivalent. If that is your main use, the honest recommendation is to stay, or move the job to an automation platform.

How do you move off HARPA without losing your commands?

HARPA stores custom commands in its own spaces. We did not find a documented bulk-export feature on its pricing or home pages, so plan for a manual pass.

HARPA MIGRATION CHECKLIST

1. List every custom command you use at least weekly. Ignore the rest.
2. Open each one and copy its full prompt text, including parameters,
   into a plain document. Note which page context it relies on.
3. Rewrite parameters as clear placeholders, e.g. [PRODUCT NAME],
   so the prompt still makes sense outside HARPA.
4. List every web monitor and scheduled command separately. These need
   an automation tool, not a prompt library or sidebar.
5. Rebuild the monitors first in your new tool and run both in parallel
   for a week.
6. Move the prompts into your new library and test each once in the
   model you will actually use.
7. Only then let the HARPA subscription lapse. Remember: no refunds.

For browser-agent tasks, rewrite the prompt as an explicit instruction list. Agents do better with a clear goal, the site to use, what not to touch, and when to stop and ask:

Goal: Find three hotels near [VENUE] for [DATES] under [BUDGET] per night.
Sites: Use only the booking site already open in this tab.
Do not: sign in, enter payment details, or book anything.
Output: A table with hotel name, price per night, distance, cancellation policy.
Stop and ask me if: a site asks for login or a captcha appears.

The bottom line

HARPA is still one of the few extensions that combines chat, page monitoring and scheduled automation, and for that combination there is no clean replacement. For any single part of it, there is now a strong specialist: Claude in Chrome or Gemini's auto browse for agent work, Sider, Monica, MaxAI or Merlin for sidebar chat, and a prompt tool for reusable instructions. Skip anything still pointing you to ChatGPT Atlas, and check each vendor's own page before you pay, because this category changes monthly.