The architecture review has reached the slide labelled browser vendor, and the shortlist on it came from a search result, a teammate and a demo call. Somebody asks which is fastest, somebody asks which is cheapest, and nobody has run them on the same test.
That is the question behind Steel vs Browserbase vs Kernel. Solari belongs on the same slide: the fastest of the four on a public benchmark, the cheapest per browser hour at list price, and the only one with sandboxes and desktops in the same account. This guide compares all four on speed, price and fit.
The Four Vendors at a Glance
Before the detail, here is where each vendor puts its weight.
Speed is where the four differ most, so it comes first.
Speed: Which Is Fastest
Speed is the number a shortlist usually argues about without data. On Steel's open-source benchmark, Solari is about 4x faster than Kernel, about 4.5x faster than Steel and about 14.8x faster than Browserbase end to end, averaging 199.9 ms across 5,000 runs with a median session create of 8 ms. The pull request is still open, so any team can rerun it.
For every vendor, the run creates a session, connects Playwright over the Chrome DevTools Protocol, loads a page and releases the session. An agent that opens a fresh browser per task pays that start time on every task, and every one of those sessions is also billed.
Price per Browser Hour
Price is the second half of the question, and the vendors publish it in different shapes. The chart shows the browser-hour rate on the plan a production team usually lands on.
Solari bills $0.05 per browser hour on Team and $0.07 on Professional, and Enterprise bills browsers at a tenth of Team's rate. Steel's Scale plan bills $0.08 per browser hour, and Browserbase's Startup plan bills $0.10 once its 500 included hours are used.
Kernel bills by the second instead. A headless Kernel browser costs $0.0000166667 per second, and it enters Standby Mode 5 seconds after its last CDP or Live View activity and stops accruing usage cost. Rates are only part of the bill, so the plans come next.
Fit: Where Each Vendor Belongs
The plans decide which vendor a team can live with, so each entry covers the plan, the fit and the trade-off.
Solari
Core capabilities. Solari starts a headless browser by API, and any recent CDP client can drive a Solari session. Profiles save a login as the cookies plus per-origin localStorage, so a later session starts signed in. Sandboxes and desktops run from one account and one API.
Pricing and plans. The Free plan costs $0 with $3 of monthly credits. Professional costs $200 a month, returns the fee as usage credits and allows 150 concurrent browsers. Enterprise runs up to 100,000 concurrent standard browser sessions.
Who it's best for. Solari fits teams whose agents open a fresh browser per task, where start time and the hourly rate both multiply with the fleet. Teams on Browserbase can migrate by changing the import and the key.
Steel
Pricing and plans. Steel's Scale plan costs $250 a month plus usage, with 100 concurrent sessions, sessions up to 1 hour and a HIPAA-ready BAA. The free Launch plan starts with a $30 one-time credit.
Where it fits. Steel Browser is open source and can be self-hosted. That suits a team that wants the browser on its own machines for development and in the cloud for production.
Trade-off. Steel includes its stealth browser on Enterprise only. A pipeline that visits sites that block automation may need a custom contract before its volume calls for one.
Browserbase
Pricing and plans. Browserbase's Startup plan costs $99 a month with 100 concurrent browsers and the included hours above. The custom Scale plan starts at 250+ concurrent browsers with HIPAA (BAA) and SSO.
Where it fits. Browserbase sells Fetch and Search APIs, a Model Gateway and Stagehand next to its browsers. A team that wants search, fetches and model billing from its browser vendor gets that bundle on one invoice.
Trade-off. Browserbase plans are priced around included hours, agent runs and API calls rather than a flat browser rate. A browser-only fleet pays for allowances it may not use.
Kernel
Pricing and plans. Kernel's free Developer plan includes $5 of monthly credits, and Start-Up costs $200 a month plus usage with $50 of credits. Start-Up runs 150 concurrent browsers.
Where it fits. Kernel includes live view, managed stealth mode, browser pools and managed auth on every plan. That suits an agent that signs in to many accounts and sits idle between steps, where Standby Mode keeps idle time off the invoice.
Trade-off. Kernel prices headless, headful and GPU browsers at separate per-second rates, so a forecast depends on the mix a fleet runs. HIPAA (BAA) is Enterprise only on Kernel.
Choosing the Right Setup
Steel vs Browserbase vs Kernel comes down to what the fleet values most: Steel for a browser it can self-host, Browserbase for search and fetch in one bundle, Kernel for managed auth and idle-free billing. When start time and the browser-hour bill decide, Solari leads all three, and the Solari launch overview shows how sandboxes and desktops share the account. 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 by pointing an existing Playwright script at a Solari session and running a day of normal traffic next to your current vendor. Solari is the fastest and cheapest of the four for that job, at the 199.9 ms average and the Team rate shown above, and the Free plan needs no contract. Create a free Solari account and run the comparison on your own workload.
