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Turbo-Browser-MCP Consolidates Browser Primitives into 10 Batched Tools

Original title: Show HN: Turbo-Browser-MCP – Batch forms, DOM deltas and submit guards for MCP
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Turbo-Browser-MCP is a Playwright-based MCP server that consolidates 25-33 fine-grained browser primitives into 10 batched tools, cutting token waste and multi-turn latency via delta DOM snapshots, single-turn form prefill and direct disk file uploads. Benchmarks show dense UI snapshots dropping from 18,654 to 1,135 tokens and post-click deltas at just 56 tokens, with a human-in-the-loop submit guard enabled by default.

Full Report

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turbo-browser-mcp

turbo-browser-mcp is a Playwright-based Model Context Protocol (MCP) server built to cut LLM token waste and multi-turn latency in browser automation. It consolidates 25-33 fine-grained browser primitives into 10 batched tools featuring delta DOM snapshots, single-turn React/Shadow DOM/iframe form prefill, direct disk file uploads (no Base64 in context), parallel tab sessions, network blocking presets, and a default human-in-the-loop Submit guard.


At-a-Glance Performance & Token Scorecard

All figures below come from benchmarks/benchmark.mjs (npm run benchmark) running headless Chromium locally with exact OpenAI o200k_base tokenization (tiktoken 0.14.0):

CapabilityTypical Baselineturbo-browser-mcpSpeed / Turn GainToken Savings (o200k_base)
Dense UI Snapshot (140-btn SaaS console)18,654 tok HTML / 3,568 tok full ARIA1,135 tok compact (28 ms)1 call93.9% vs HTML (68.2% vs ARIA)
Post-Click Delta Snapshot (onlyChanged: true)3,582 tok full ARIA rescan56 tok changed lines (18 ms)1 call98.4% vs ARIA (99.7% vs HTML)
10-Field Complex Form + Snapshot (smart_fill_form)11 turns (574 ms, 12,197 dir / 72,614 cum tok)1 turn (82 ms, 811 tok)7x faster, 11 -> 1 turns93.4% direct / 98.9% cumulative
48 KiB PDF Upload (49,152 bytes)44,728 tok inline Base64 tool arg85 tok disk path (68 ms)Zero Base64 generation99.8% saved
6-Step Interactive UI Flow (batch_actions)6 turns (411 ms, 955 dir / 3,162 cum tok)1 turn (357 ms, 406 tok)1.15x faster, 6 -> 1 turns57.5% direct / 87.2% cumulative
Open 6 Tabs Concurrently (open_many)6 turns sequential (998 ms)1 turn batched (420 ms)2.38x faster, 6x fewer turns5 fewer prompt replays
Heavy Media Load (preset: "turbo", 304 KiB assets)252 ms, 9 media requests (304 KiB)165 ms, 0 media requests (0 KiB)1.53x faster100% media bandwidth cut
Article Markdown Scraping (extract_clean_text)3,595 tok raw HTML (10,844 chars)156 tok clean Markdown (641 chars)Clean reader output95.7% saved
Diagnostics Triage (page_diagnostics errors-only)3,460 tok unfiltered (32 req / 26 console)601 tok default errors (2 req / 6 console)Zero noise scrolling82.6% saved
Static MCP Tool Schema (every turn overhead)3,917 tok Playwright / 6,737 tok DevTools3,010 tok stripped (3,314 full w/ annotations)10 tools vs 25 / 3323.2% vs Playwright / 55.3% vs DevTools

Note on latency vs LLM inference turns: Eliminating 10 round-trips on a 10-field form saves both 7x in browser execution (574 ms -> 82 ms) and 10 separate LLM inference round-trips (2-5s per turn in agent loops) plus ~71,800 replayed history tokens.


Why Browser Agents Stall: Side-by-Side Workflow

Standard MCP servers charge an LLM round-trip for every snapshot, field fill, <select> choice, upload, and verification check. Each turn re-sends the growing conversation history back into the model.

Diagram

(注:更多技术实现细节与完整 API 文档请查阅原项目 README)