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Firefox DevTools MCP vs Siteglass MCP

A side-by-side look at the Firefox DevTools MCP and Siteglass MCP MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.

Firefox DevTools MCP logoFirefox DevTools MCPBrowser Automation · Local subprocess (stdio)Control and debug Firefox: navigate, fill forms, inspect network and console, profile.72GreatAuth: no auth requiredSiteglass MCP logoSiteglass MCPBrowser Automation · Local subprocess (stdio)Archive any URL to a shareable rrweb/pdf/png snapshot + agent-driven web QA (scan, run E2E flows).51GoodAuth: not declared

Verdict: choose Firefox DevTools MCP for browser automation work as a local process; choose Siteglass MCP for browser automation as a local process. You can also run both side by side in one mcpServers block.

Which MCP server should you choose?

Firefox DevTools MCP logoChoose Firefox DevTools MCP when

  • You need dedicated capabilities in the Browser Automation domain.
  • You prefer a local stdio subprocess transport.
  • Its auth model fits you: No auth required.
  • You want tools like list_pages, new_page, navigate_page.
Explore Firefox DevTools MCP

Siteglass MCP logoChoose Siteglass MCP when

  • You need dedicated capabilities in the Browser Automation domain.
  • You prefer a local stdio subprocess transport.
  • You have the keys it needs: SITEGLASS_API_KEY.
  • You want tools like siteglass_scan_local, siteglass_render, siteglass_get_render.
Explore Siteglass MCP

Feature & specification comparison

Rows where the two servers differ are marked.

SpecFirefox DevTools MCP logoFirefox DevTools MCPSiteglass MCP logoSiteglass MCP
CategoryBrowser AutomationBrowser Automation
Quality signal72/100 · Great51/100 · Good
Install commandConfirmedConfirmed
TransportLocal subprocess (stdio)Local subprocess (stdio)
AuthNo auth requiredNot declared
PricingFreeNot declared
Required env varsNone listedSITEGLASS_API_KEY
Verified ownerCommunity listingCommunity listing
GitHub stars5200
Directory activity 6 views 0 installs 0 upvotes 0 views 0 installs 0 upvotes
Tools3510
Full listingView Firefox DevTools MCP View Siteglass MCP

Tools & capabilities

Firefox DevTools MCP tools 35

  • list_pagesList open tabs (index, title, URL). Selected tab is marked.
  • new_pageOpen new tab at URL. Returns tab index.
  • navigate_pageNavigate selected tab to URL.
  • select_pageSelect active tab by index, URL, or title. Index takes precedence.
  • close_pageClose tab by index.
  • get_page_textGet the visible text of the page (document.body.innerText). Caps at maxLength (default 20000 chars); saveTo saves the full text to a file.
  • take_snapshotCapture DOM snapshot with stable UIDs. A UID stays valid across snapshots until its element is removed or the page navigates. Output caps at maxLines (default 100); scope with selector or dump the full tree with saveTo.
  • resolve_uid_to_selectorResolve UID to CSS selector. Fails if the element is gone.
  • clear_snapshotClear snapshot UIDs. Usually not needed.
  • click_by_uidClick element by UID. Set dblClick for double-click.
  • hover_by_uidHover over element by UID.
  • fill_by_uidFill text input/textarea by UID.
  • +23 more on the listing page

Siteglass MCP tools 10

  • siteglass_scan_localfree, no-auth** — crawl a local/dev app in a browser on your machine → analyzed findings + report
  • siteglass_renderarchive any public URL → shareable snapshot permalink (rrweb / pdf / png); no CAPTCHA, no signup
  • siteglass_get_renderfetch an archive once its Lightning invoice is paid
  • siteglass_register_siteregister an app URL, get an ownership-proof token
  • siteglass_verify_siteconfirm the token is live (DNS TXT or hosted)
  • siteglass_scancrawl the site → report + findings (first scan free)
  • siteglass_generate_flowsderive executable E2E test flows from a scan
  • siteglass_run_flowrun a flow → per-step pass/fail, screenshots, video, rrweb replay
  • siteglass_set_credentialsgive a test login for authenticated flows
  • siteglass_feedbacksend feedback to the siteglass team

Ready-to-paste client configs

Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.

Firefox DevTools MCP

mcpServers (Claude Desktop / Cursor)
{
  "mcpServers": {
    "firefox-devtools-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@mozilla/firefox-devtools-mcp@latest"
      ]
    }
  }
}

Siteglass MCP

mcpServers (Claude Desktop / Cursor)
{
  "mcpServers": {
    "mcp-356": {
      "command": "npx",
      "args": [
        "-y",
        "siteglass-mcp"
      ],
      "env": {
        "SITEGLASS_API_KEY": "YOUR_SITEGLASS_API_KEY_HERE"
      }
    }
  }
}

Frequently asked questions

Firefox DevTools MCP is categorized under Browser Automation and uses a local stdio subprocess. Siteglass MCP belongs to Browser Automation and uses a local stdio subprocess. Pick Firefox DevTools MCP for browser automation work and Siteglass MCP for browser automation.

Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.

Firefox DevTools MCP is listed as free. Auth: no auth required. Siteglass MCP has no declared pricing — check the project's own site. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.

Yes. MCP clients support multiple servers: add firefox-devtools-mcp and mcp-356 as separate keys in the same mcpServers object, and your assistant will call tools from either one.

On AllMCPs, Firefox DevTools MCP has a quality signal of 72/100 (Great) with 6 views, 0 installs and 520 GitHub stars. Siteglass MCP has 51/100 (Good) with 0 views, 0 installs and 0 GitHub stars.

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