Every AI agent that does real work now needs a browser of its own. Models already operate a screen, a mouse and a keyboard on their own, and most of the work they do for a business happens on websites.
That makes the browser part of your infrastructure. The best cloud browser infrastructure for AI agents starts sessions fast, keeps logins between runs, gets through sites that block automation and stays affordable at fleet scale, and Solari is the strongest fit on all four. On Steel's open-source benchmark, a Solari session averaged 199.9 ms end to end across 5,000 runs, about 4x faster than Kernel, about 4.5x faster than Steel and about 14.8x faster than Browserbase, with Solari's results in a pull request that is still open. This guide covers what your agents need from a browser, then compares Solari with Browserbase, Steel, Kernel and Hyperbrowser on speed, pricing and fit.
Why Does Browser Infrastructure Matter More in 2026?
Browser automation used to mean a test suite or a scraper: a few headless browsers on a server, run on a schedule and watched by the engineer who wrote them. A slow start or a lost login cost a retry.
Agents change the load. An agent opens a fresh browser for each task, signs in to real accounts and runs at all hours with nobody watching, so every second of start-up and every repeated login multiplies across thousands of sessions a day. The vendor you pick decides how long your agents wait and what the monthly bill looks like.
What Should Cloud Browser Infrastructure Do for Your Agents?
Cloud browser infrastructure should let your agent do six jobs without you running Chromium yourself:
Start a browser for every task. A cloud browser is a Chromium session started by API, driven over the Chrome DevTools Protocol or Playwright, and released when the task ends. Your agent pays the start-up time on every task, so a fast start keeps the fleet moving.
Keep logins between runs. The browser should save cookies and site data so your agent signs in once. Without that, each task begins at a login page.
Get through sites that block automation. Many sites challenge automated traffic with a CAPTCHA or filter it by network. Stealth settings and a proxy chosen per session decide whether the job finishes.
Run a fleet in parallel. A territory list or a nightly crawl finishes on time only when the browsers run side by side. Your vendor's concurrency sets how many tasks run at once.
Show what the agent did. When an agent acts under your company's name, someone needs to see what it read and clicked. A session recording gives you that record.
Run code beside the browser. Many agents write and run code, then use a website to file the result. Keeping both with one vendor saves a second contract and a second set of keys.
The Options at a Glance
Each vendor answers those jobs differently, and the table groups them by the niche each one fills.
Solari comes first because it covers all six jobs from a single account.
1. Solari
Solari is agent infrastructure from Pinetree Research: cloud browsers, sandboxes and desktops from one API. You bring the model and the agent logic; Solari supplies the environment your agent runs in.
A browser for every task. Solari browsers are ready in 8 ms, so your agent opens a fresh session per task without waiting in a queue. Across thousands of tasks a day, your fleet spends its time working.
Logins that stay signed in. A Solari profile saves your login, cookies and site data in Playwright's storage state format, so every later session opens already signed in. For sites that ask again, auto-login fills the username, password and one-time code from 1Password without your agent ever seeing the credential.
Sites that block automation. Turn on stealth per session, route traffic through a proxy in the country you choose, and let Solari solve the CAPTCHA when reCAPTCHA, hCaptcha or Cloudflare Turnstile appears. Every other site runs on the faster default browser.
A whole fleet, for less. With Solari you can launch up to 100,000 browser sessions at once, so you can run a full account list in one pass instead of overnight. At list price, Solari costs less per browser hour: about 2x cheaper than Browserbase and about 1.6x cheaper than Steel. Stealth sessions carry their own, lower cap, so size that cap first if most of your fleet runs in stealth.
A record of every run. Record a session and replay it in the console, or download it as a line-by-line log. Recording captures input values by default, so leave it off for sessions that type secrets.
Solari sandboxes run the code your agent writes, and Solari desktops give a computer-use model a full Linux screen, all on one account and one bill. Solari works with Playwright, Puppeteer and any CDP client, so a trial runs your existing agent code on your real workload.
2. Browserbase
Browserbase is the incumbent of the category and the alternative most teams compare first.
Pricing and plans. Browserbase charges $20 a month for 25 concurrent browsers and 100 browser hours, then $0.12 per browser hour, and $99 a month for 500 browser hours with $0.10 per hour after that. A team inside its included hours pays a flat fee, and overage is where the bill grows.
Where it shines. Browserbase bundles web search and fetch calls with every plan, alongside agent runs. A team that wants search and the browser from one vendor gets both.
Trade-off. Browserbase's no-cost tier keeps sessions short and leaves out captcha solving. Its speed gap to Solari is also the widest of the four, which matters most for agents that open a browser per task.
3. Steel
Steel is an open-source browser API for agents, built by a team that publishes its own performance work in the open.
Pricing and plans. Steel charges $250 a month plus usage for 100 concurrent sessions, sessions up to 1 hour and browsers at $0.08 per hour. Concurrency is fixed by plan, which gives you a known ceiling on launch day.
Where it shines. Steel Browser is open source and can be self-hosted. A team with data-residency rules can keep the browser inside its own network.
Trade-off. Steel keeps its stealth browser and day-long sessions for custom contracts. Logged-in agents on hard-to-reach sites meet a contract step sooner than on a self-serve plan.
4. Kernel
Kernel is browser infrastructure for agents built around managed logins, and its billing rewards agents that wait.
Pricing and plans. Kernel's headless browsers bill at $0.0000166667 per second of active runtime and enter standby 5 seconds after their last CDP or Live View activity, when usage stops accruing. Cost follows active time rather than a flat hourly rate.
Where it shines. Kernel includes stealth mode with a captcha solver and proxy, plus managed auth, on its no-cost tier. An agent that spends most of a task waiting on a model pays only for the time it works.
Trade-off. Active-runtime billing is precise but harder to forecast than an hourly rate. Kernel also keeps HIPAA for custom contracts.
5. Hyperbrowser
Hyperbrowser sells browsers, sandboxes, web data APIs and hosted agents from a shared credit balance.
Pricing and plans. Hyperbrowser charges $30 a month with the same amount included as usage and 25 concurrent sessions, and browsers cost $0.10 per hour on every self-serve plan. A bigger plan buys capacity and features rather than a lower rate.
Where it shines. One Hyperbrowser balance covers browsers, sandboxes and fetch or search calls. A team that wants a hosted agent loop and web data APIs beside the browser gets them without a second vendor.
Trade-off. Hyperbrowser starts basic stealth on its entry paid tier and keeps ultra stealth mode for custom contracts. If your fleet is sensitive to start-up time, run your own timing trial before you commit.
Where Is Browser Infrastructure for Agents Heading?
Most agents today run one task in one browser. Over the next year that changes in four ways:
Agents that run all day will hold a browser and a login for hours, pausing between steps instead of starting over.
Computer-use models will work in apps with no web page, moving between a browser and a desktop in the same task.
More sites will tell trusted agents apart from unwanted bots and treat them differently.
As fleets grow, teams will compare vendors on cost per finished task rather than a plan's sticker price.
What stays human is judgment: which sites your agents may act on, which accounts they may sign in to and which actions need a person's approval. The teams that win will spend their people on those calls and hand the clicking to agents.
Which Cloud Browser Should You Choose?
Choose by the job that matters most to your agents. Browserbase fits a team that wants web search beside the browser, Steel a team that must self-host, Kernel agents that sit idle between steps and Hyperbrowser a hosted agent loop on a shared credit balance.
Choose Solari when session speed, saved logins and fleet size decide the build, or when your agent also needs a sandbox or a desktop. Browserbase is the more established vendor with the larger ecosystem; Solari is the younger company and moves faster on speed and price.
Get Started With Solari
Start with one job your agents already run, such as a nightly sign-in to a customer portal: attach a profile, point its Playwright code at a Solari browser and compare the run with your current vendor at the same concurrency. Solari is the fastest and cheapest way to run cloud browsers and VMs for web agents. Get started with a free account and start running your agents today.
