Ship & watch AI apps
Best AI app infrastructure in 2026: 4 tools compared
4 tools · Updated Sep 6, 2026
A model on its own does very little. The moment an AI app leaves the notebook it needs plumbing, and this category is the plumbing: getting web content in, running the code the model wrote somewhere that cannot hurt you, and being able to see afterwards what the thing actually did. Four tools, four different jobs, and the fastest way to lose a week is to pick the wrong one. Firecrawl reads a page and hands back clean text — no browser, no clicking, just the content. Browser Use drives a real browser instead, clicking and typing through sites that have no API, which is slower and less predictable but the only option when the interface was built for people. E2B gives model-written code a disposable computer to run on, so nothing it invents touches your machine. Langfuse records what happened: which prompt went out, what came back, what it cost, where it broke. The other thing to settle early is what "free" means here, because it means two different things. Firecrawl and Langfuse renew a monthly allowance — 1,000 credits and 50,000 units. E2B and Browser Use give you a one-time credit instead — $100 and $15 — and when it is spent you are on the meter.
Side by side
| Tool | Best for | Free tier | From |
|---|---|---|---|
| Firecrawl | Anyone feeding web content to an AI: RAG, agents, research pipelines. | 1,000 credits a month — roughly 500 searches or 1,000 pages — with 2 concurrent requests and no card. It renews monthly. | from $16/month |
| Browser Use | Developers building agents that operate real websites where no API exists. | A one-time $15 credit for eligible Google, GitHub and Microsoft signups, with 10 concurrent sessions and cheaper models only. It does not renew. | Usage-based |
| E2B | Anyone building a coding agent or a code-interpreter feature that has to execute model-written code somewhere. | A one-time $100 usage credit — not a monthly allowance — with 1-hour maximum sessions and 20 concurrent sandboxes. | from $150/month |
| Langfuse | Teams that want tracing, prompt management and evals in one open-source, self-hostable tool. | 50,000 units a month on the hosted Hobby plan, with 30-day retention and two users, no card. Self-hosting the MIT core has no usage limits. | from $29/month |
How we picked
Four criteria. Each is free to start, though "free" splits two ways here: Firecrawl renews 1,000 credits a month and Langfuse 50,000 units, while E2B's $100 and Browser Use's $15 are one-time credits that never renew. Each publishes what it is licensed under — Browser Use MIT, E2B Apache-2.0, Langfuse's core MIT with a source-available Enterprise Edition, Firecrawl's core AGPL-3.0 with MIT SDKs. Each can be self-hosted, with the caveat that Firecrawl's self-hosted build does not carry the cloud's anti-bot layer. And each is alive: Firecrawl at 177,312 GitHub stars, Browser Use at 112,754, Langfuse at 34,268 and E2B at 13,686, all pushed within days of 6 September 2026. Prices come from each vendor's own pricing page, read on 6 September 2026. We have not tested them hands-on.
The tools
Firecrawl
from $16/monthTurns a web page into clean text an AI can read. A recurring free tier: 1,000 credits a month, no card.
Browser Use
Usage-basedBrowser Use is a product, not a phrase: it puts an AI agent in a real browser to click, type and finish web tasks.
E2B
from $150/monthA safe, disposable computer for code your model wrote. The free tier is a one-time $100 credit, not a monthly allowance.
Langfuse
from $29/monthOpen-source tracing for AI apps: what went out, what came back, what it cost. Free for 50,000 units a month.
Which one should you start with?
Start with Firecrawl. The first thing almost every beginner's AI app needs is the contents of a web page in a form a model can read, and Firecrawl does that in one call — no browser to drive, no sandbox to configure. Its free tier renews at 1,000 credits a month, roughly 500 searches or 1,000 pages with no card, which is enough to find out whether your pages come back clean. Add Browser Use only when reading is not enough and something has to be clicked or logged into. Bring in E2B once your app runs code the model wrote, and Langfuse when you have shipped enough to need an answer to "why did it do that?"
Questions people actually ask
- Why does an agent need a sandbox?
- Because the code was written by a model and the only way to know what it does is to run it. A sandbox is a disposable computer somewhere else: the code runs there, you keep the output, the machine is destroyed. Nothing reaches your laptop or your production server. E2B is the tool here that does that job — Hobby is $0 plus usage with a one-time $100 credit, one-hour sessions and 20 concurrent sandboxes.
- What is LLM observability?
- A record of what your AI app did, detailed enough to explain a bad answer later: the prompt that went out, what came back, what the call cost, and where it broke. Ordinary application logs do not capture that in a usable shape. Langfuse stores each call as a trace and adds evals and prompt management, free for 50,000 units a month on the hosted plan, or with no usage limits on the MIT core if you self-host.
- Firecrawl or Browser Use?
- Read a page versus drive a browser. Firecrawl fetches a URL and returns clean text: no browser session, cheaper, more predictable. Browser Use puts an agent in a real browser to click, type and log in, which is what a site with no API requires. If you only need the words on the page, the first is the right tool; if the task involves a form or a login, the second. The name Browser Use collides with the ordinary phrase, so search for the repository, browser-use.
- How much of this is actually free?
- Two of the four renew. Firecrawl gives 1,000 credits a month, around 500 searches or 1,000 pages, with two concurrent requests and no card. Langfuse gives 50,000 units a month with 30-day retention and two users, and self-hosting its MIT core has no usage limits. The other two do not renew: E2B's Hobby plan carries a one-time $100 usage credit, and Browser Use a one-time $15 signup credit gated to eligible Google, GitHub and Microsoft accounts.
- Can I self-host all four?
- Yes, with two caveats. Browser Use is MIT, and E2B is Apache-2.0 and deployable through Terraform, Nomad and Consul on GCP, with AWS in beta. Langfuse's core is MIT and self-hostable, but SCIM, audit logging and retention policies sit in a source-available Enterprise Edition that needs a paid licence key even on your own servers. Firecrawl self-hosts under AGPL-3.0 — and the self-hosted build lacks the managed anti-bot engine and stealth proxying the cloud product uses on difficult sites.
- Who owns these tools?
- One ownership change is worth knowing about. ClickHouse acquired Langfuse on 16 January 2026, bundled into ClickHouse's $400M Series D at a $15B valuation; the announcement says the project stays open source and self-hostable with an unchanged roadmap. No comparable ownership change is recorded for the other three: Firecrawl raised a $14.5M Series A in August 2025, E2B a $21M Series A in July 2025, and Browser Use $17M as of March 2025.
Research-compiled, not hands-on tested. Compiled from official docs, the vendor's pricing page and community reviews as of Sep 6, 2026. We haven't tested it hands-on yet.