RenderLens
Visual verification MCP server — render code to screenshots, run WCAG accessibility audits, and pixel-diff UI changes. Free, no API key.
MCP Server for Claude, Cursor & AI agents
Give your AI agent
eyes to verify what it builds
RenderLens renders, audits, and diffs UI code in real time. Your AI sees exactly what users will see — pixel by pixel.
Get Started Free See How It Works
100 free calls/month — no signup needed. Just point your AI agent and go.
📸
render()
Screenshot of your HTML/React code. See what users will see.
♿
audit()
Lighthouse + WCAG accessibility scores in one call.
🔀
diff()
Pixel-level visual diff between two code versions.
Why RenderLens?
Your AI writes UI code but can't see the result. RenderLens fixes that.
⚡
Zero setup
One command and you're live. No Playwright to install, no browser to manage, no Docker to configure.
⏳
2-second renders
Fast enough for iterative loops. Write code, render, fix, re-render — all in a single conversation.
♻
Tailwind built-in
Tailwind CSS classes work out of the box. Inject your project's CSS variables and Google Fonts too.
🔒
Code never stored
Your code is processed in memory and discarded immediately. Nothing is logged or persisted.
Three tools. Complete visual verification.
Each tool is designed for a specific step in the AI coding workflow.
Render
Takes HTML or React code and returns a JPEG screenshot. Supports custom viewports, full-page capture, and quality settings.
- ✓ Auto-detects HTML vs React
- ✓ npm packages via CDN
- ✓ Console errors captured
// AI agent calls render tool
{
"code": "<div class='card'>...</div>",
"viewport": { "width": 1280 },
"quality": 80
}
// Returns: JPEG screenshot + metadata
Audit
Runs Lighthouse and axe-core accessibility audit. Returns scores, WCAG violations with severity and remediation hints.
- ✓ WCAG 2.1 A/AA/AAA
- ✓ Lighthouse categories
- ✓ Actionable fix suggestions
// Audit response
{
"lighthouse": { "accessibility": 100 },
"wcag": {
"violationsCount": 0,
"passesCount": 12
},
"summary": "PASS: No violations"
}
Diff
Compares two code versions pixel by pixel. Returns a diff image highlighting changes and a percentage metric.
- ✓ Pixel-level precision
- ✓ Configurable threshold
- ✓ Visual regression detection
// Diff response
{
"diffPercentage": 3.2,
"diffPixels": 29491,
"verdict": "CHANGED: 3.2% differ"
}
// + diff image overlay
Get started in 3 steps
1
Add the config
Copy the snippet below into your MCP client. No API key needed for trial.
2
Try 100 free calls
Render, audit, and diff immediately. No signup, no credit card.
3
Build with confidence
100 calls/month free during beta. Paid plans coming soon.
Claude Code
One command — no signup needed
$ claude mcp add renderlens --transport http https://app.renderlens.dev/mcp
Or add to Cursor, Windsurf, or any MCP client config:
{
"mcpServers": {
"renderlens": {
"type": "streamable-http",
"url": "https://app.renderlens.dev/mcp"
}
}
}
Free during beta
Try RenderLens free. Paid plans coming soon.
Free Beta
Beta
Free
100 calls/month
- ✓ 100 free calls/month — no signup needed
- ✓ All 3 tools included (render, audit, diff)
- ✓ No API key required
- ✓ No credit card required Get Started
Paid plans with higher limits coming soon.
Related Servers
Alpha Vantage MCP Server
sponsorAccess financial market data: realtime & historical stock, ETF, options, forex, crypto, commodities, fundamentals, technical indicators, & more
MCP Inspector
A developer tool for testing and debugging MCP servers with a web UI and proxy.
AgentPM
A planning and orchestration system for AI-driven software development.
Manual Tests MCP Server
A YAML-based server for managing manual test cases with tools for test automation workflows.
Chart
A Model Context Protocol server for generating visual charts using AntV.
Health Microservice API
A FastAPI microservice for health-related operations, featuring JWT authentication and a PostgreSQL database with Alembic migrations.
Remote MCP Server (Authless)
An example of a remote MCP server without authentication, deployable on Cloudflare Workers.
ScreenHand
Native desktop + browser automation MCP server with 82 tools — accessibility APIs (macOS/Windows), Chrome DevTools Protocol, anti-detection, memory, jobs, and reusable playbooks.
Shopify Dev
A command-line tool for interacting with Shopify's Admin GraphQL API, Functions, and Polaris Web Components.
VibeCoding System
A conversation-driven development framework for rapid MVP and POC creation.
Excalidraw MCP
Generate 25+ diagram types (flowchart, sequence, ER, mindmap, architecture, etc.) as Excalidraw files with natural language. CJK support, 30+ tech brand colors, Sugiyama auto-layout.