The browser is now the line on an agent's bill that grows fastest. Models with computer use read pages, fill forms and click through sites on their own, and teams run them by the thousand every day, each run holding a cloud browser open while the meter turns.
That makes cost per session a number the engineer who owns the pipeline has to answer for. The cheapest way to run browser agents in production is to pay the lowest hourly rate your volume reaches, choose a plan whose fee comes back as usage, and close every session the moment its task ends. This guide prices each input across Solari, Browserbase, Steel, Hyperbrowser and Kernel, then sets out what you can do to cut the bill.
Why Does Cost per Session Matter Now?
Cost per session matters because the bill grows with runs, not with seats. A pilot of a few hundred runs disappears inside a plan fee; a fleet running thousands of tasks a day turns every extra minute into a line on the invoice.
The arithmetic is shared: take the average minutes a session stays open, divide by sixty and multiply by the hourly rate. Add the gigabytes sent through a proxy and the CAPTCHA solves at their own rates, and you have the cost of one run.
The input teams underestimate is the open minutes. A headless browser waiting on a slow page, or orphaned by a crashed script, keeps the meter running. Solari bills browsers per hour while a session is open, so a session closed the moment its task ends pays only for the time it worked.
What Do Browser Hours and Proxies Cost at List Price?
Solari has the lowest browser-hour rate and the lowest proxy rate of the vendors charted below, and an Enterprise contract brings its browser rate down to a tenth of Team's rate.
Solari's captcha solves cost $0.005 each on Professional, and proxies and captcha solving run only in stealth sessions, so you pay for them only on sites that need them.
How Do Plan Fees and Included Usage Compare?
A plan fee is cheap only when it comes back as usage; when it does not, it raises the cost of every run at low volume.
Solari returns all of it on self-serve plans. Starter costs $20 a month and Professional $200, and both fees come back as credits that refill monthly. Usage stops at the balance, so you never see an overage charge.
Steel. Steel says its Scale plan costs $250 a month plus usage with a $100 monthly credit, and bills $0.08 per browser hour, $6 per GB of proxy and $1 per 1k CAPTCHA solves, with sessions up to 1 hour. Part of the fee is a platform charge, so the rate pays off only once your volume grows into it. Steel's open-source browser suits teams that may self-host later.
Browserbase. Browserbase says its Startup plan costs $99 a month and includes 500 browser hours, then bills $0.10 per browser hour. A team that uses most of those hours gets a fair rate; a team that runs fewer pays for hours it never uses.
Hyperbrowser. Hyperbrowser says its Startup plan costs $30 a month with $30 of usage included, and bills browsers at $0.10 an hour and proxy data at $10 per GB. The whole fee comes back as usage, but the browser rate stays the same from the free plan up, so it does not fall as volume grows.
Kernel. Kernel says its Start-Up plan is $200 a month plus usage with $50 in credits, a headless browser costs $0.0000166667 per second, and a browser enters Standby Mode 5 seconds after its last activity and stops accruing usage cost. Standby billing suits agents that idle between steps; the trade-off is a fee that sits on top of usage, and per-second billing keeps Kernel off the hourly chart.
What Can You Do to Cut Cost per Session?
Most of the saving sits in your own code and settings, not in the rate. These changes pay back first:
Close every session in a finally block. Call browser.close(), or
release(id)for sessions created directly, in a finally block that runs whether the task succeeds or throws. A crashed script no longer leaves a browser running overnight.Turn on stealth per site. Run stealth, proxies and captcha solving only for sessions that reach a protected page. Every other site pays for browser time alone.
Skip heavy files on proxied sessions. Solari's blockHeavy setting makes the browser refuse video, audio and large images, so they never cross the proxy. Media-heavy pages stop inflating the per-GB line.
Sign in once with profiles. A Solari profile saves your login, cookies and site data, so every later session starts already signed in. Your agent stops spending billed minutes on login pages.
Set timeouts below the session cap. If a bug skips the close, Solari ends the session at the plan's cap: 1 hour on Free, 5 hours on Starter and 24 hours on Professional. Shorter timeouts of your own make a stuck run cost minutes instead of hours.
What Role Does Solari Play?
Solari is the infrastructure a browser agent runs on: cloud browsers, sandboxes and desktops from one API. Your agent brings the logic; Solari keeps each run fast and the bill predictable.
A lower rate from the first run. Solari is about 2x cheaper than Browserbase and about 1.6x cheaper than Steel per browser hour at list price, with no change to how your agent works.
Browsers that start at once. Solari browsers are ready in 8 ms, so you can open a fresh session per task instead of keeping one idle between jobs.
A whole list in one pass. Solari supports up to 100,000 concurrent browsers on Enterprise, so you can run thousands of tasks at once instead of queuing them through the night.
A ceiling you know in advance. Browsers, sandboxes, VMs, proxies and captcha solves draw from one credit balance, and Solari stops at the balance rather than billing past it.
The agent you already have. Solari works with Playwright, Puppeteer and any client that speaks the Chrome DevTools Protocol, and Browserbase code runs on Solari sessions by changing the import.
Solari sandboxes run the code that parses what the browser collects, on the same bill. Browserbase is the more established vendor with the larger ecosystem; Solari is the younger company and moves faster on speed and price.
Which Setup Is Cheapest for Your Fleet?
The cheapest setup pairs the lowest hourly rate with a plan fee that comes back as usage, and Solari offers both. Hyperbrowser also returns its fee as usage, Kernel's standby billing helps agents that sit idle between steps, and Steel and Browserbase charge a fee that pays off only at the volume it was priced for. Whichever vendor you choose, the biggest saving comes from your own code: close sessions in a finally block, use stealth and proxies only where a site requires them, and keep logins in profiles.
Billing across the category is moving toward cost per finished task rather than cost per hour. What stays human is the judgment about which runs are worth paying for: which sites, how often, and what result justifies the spend.
Get Started With Solari
Measure the average open minutes of your current runs first, then price them at Solari's rate. Solari is the fastest and cheapest way to run cloud browsers and VMs for browser agents. Get started with a free account and start running your agents today.
