← Tap · Blog

# Stagehand vs Tap: AI Browser Automation Compared

April 9, 2026 · Leon Ting · 5 min read

Stagehand is the other major AI browser automation framework alongside Browser Use. Built by Browserbase on Playwright, it offers a cleaner API — `page.act()`, `page.extract()`, `page.observe()` — and better Playwright integration.

But Stagehand shares the same fundamental architecture as Browser Use: it calls the LLM on every step of every run. Same cost per run. Same reliability floor. Same non-deterministic outputs.

Tap takes a fundamentally different approach: compile AI understanding into a deterministic program once, run it forever at $0.

## Architecture: Interpreter vs Compiler

| Stagehand | Tap
--- | --- | ---
Model | Interpreter (LLM at runtime) | Compiler (LLM at forge time)
LLM calls per run | Every step | 0 (after first compile)
Cost per run | $0.50–$2.00 | $0
Consistency | 60–95% | 100% deterministic
Execution speed | Seconds to minutes | <1s
Offline capable | No (needs LLM) | Yes

The architectural difference is the same as Python vs compiled C: flexibility at runtime vs speed and reliability. For production automation you run daily, you want the compiler.

## Where Stagehand Excels

Stagehand is genuinely well-designed for its use case. Credit where it's due:

- Clean Playwright integration. If you're already in the Playwright ecosystem, Stagehand fits naturally.
- Ad-hoc interactions. `page.act("click the login button")` is elegant for one-off tasks.
- Flexible extraction. `page.extract({ instruction: "...", schema: z.object({...}) })` makes structured extraction easy.

These strengths are real — for tasks you'll never repeat. The problem is scale.

## The Scale Problem

Stagehand's per-run cost is fine at 5 runs/day. At 100 runs/day, you're paying $50–$200/day. At production scale with 10 automations running every 5 minutes, you're looking at $3,600/month minimum.

And cost isn't even the biggest problem. Reliability is.

When you run the same Stagehand extraction 100 times:

- Some runs return 15 rows, others 12, others 17
- Some runs extract the wrong element
- Some runs time out on LLM calls
- There's no way to detect which runs are wrong — output variance is by design

You can't monitor what you can't define. If the output is different every time, you have no baseline for health checks.

## What Tap Does Differently

    # Forge: AI inspects the site once and compiles a program
    $ tap forge https://reddit.com/r/programming
    ✓ Inspected: REST API detected at oauth.reddit.com
    ✓ Verified: 25 rows, score 95/100
    ✓ Saved: reddit/hot.tap.js

    # Run: deterministic, instant, $0
    $ tap reddit hot              # Always 25 rows, same schema
    $ tap reddit hot              # Always 25 rows, same schema
    $ tap reddit hot              # Always 25 rows, same schema

The program is plain JavaScript. It doesn't call an LLM. It doesn't reinterpret the page. Same input → same output, every single time.

## Breakage Detection and Self-Healing

When a website changes, deterministic programs break — but they break loudly, not silently:

    $ tap doctor --auto reddit hot
    ✗ selector div.thing — gone since last run
    ⚠ fingerprint diff: ↑ 2 structural changes
    ✓ heal bundle ready — current code + git history + page snapshot

Doctor tells you exactly what changed and packages everything your AI needs to fix it. AI browser agents return empty arrays for days before anyone notices — they can't detect breakage because variance is their normal state.

## Feature Comparison

Feature | Stagehand | Tap
--- | --- | ---
AI at runtime | Yes (every step) | No (zero AI at runtime)
AI at forge time | N/A | Yes (inspect → verify → save)
Deterministic output | No | Yes
Cost at scale | Linear with runs | $0 marginal cost
Breakage detection | None | Doctor + fingerprint diff
Self-healing | No | Doctor diagnostics + AI heal
MCP native | No | Yes (40+ tools)
Playwright support | Yes (built on it) | Yes (headless runtime)
Chrome extension | No | Yes (real browser sessions)
macOS native | No | Yes (Accessibility API)
Pre-built skills | None | 140+ across 68+ sites
Offline execution | No | Yes

## When to Use Each

Use Stagehand when:

- You need ad-hoc, one-off browser interactions
- You're already deep in the Playwright ecosystem and need AI-powered flexibility
- Your tasks are non-repeating and exploratory

Use Tap when:

- You run the same automation more than once
- You need reliable, consistent output
- You want zero per-run cost at scale
- You need health monitoring and self-healing
- You want MCP integration with Claude Code, Cursor, or other agents

The best part: they're not mutually exclusive. Use Stagehand for exploration. Use Tap for production. When you find yourself running the same Stagehand script daily, that's when you `tap forge` it and let the compiler take over.

### Compile your first automation

    $ npx -y @taprun/cli --version
    $ tap forge https://news.ycombinator.com  # Tier 0 — no AI needed
    $ tap hackernews hot            # $0 per run, forever