Compare / browsers

Firefox vs Camoufox

Stock Firefox against the anti-detect fork built on it: what Camoufox changes in what a site sees, what it costs you as a developer, and when plain Firefox is the better tool.

Firefox Camoufox

Firefox on the fleet is Playwright's own build (150 today): Mozilla's engine with the patches Playwright needs to drive it, nothing hidden, nothing spoofed. Camoufox (152) is a fork of that same engine whose purpose is the opposite: to look like a particular real person's computer — operating system, screen, GPU, fonts, locale, timezone and location generated at launch and answered consistently from inside the engine. Same Playwright client (firefox), same rendering engine, same TLS stack; very different answers to "who are you?". Both were launched headful through the same proxy for this page.

As a developer: driving them

	Firefox	Camoufox
Build	Playwright's Firefox 150 (`firefox` endpoint, `headless: false` or `true`).	Camoufox 152 (`camoufox` endpoint; `headless: false` virtual display, or `true`); pinned `version: "150"` available.
Launch options	The common set: `proxy`, `proxy_rules`, `headless`, timeouts.	The common set plus the persona: `os`, `locale`, `geoip`, `humanize`, `screen`, `window`, `fonts`, `webgl_config`, `fingerprint`/`config`, `ff_version`, `block_images`/`block_webrtc`/`block_webgl`, `main_world_eval`.
Where `page.evaluate` runs	In the page's world (measured): a page `<script>` sees globals you set.	In an isolated world (measured): the page can't see your globals and your checks don't see the persona unless you set `main_world_eval: true` and prefix expressions with `mw:` (measured: works).
`addInitScript`	Visible to page scripts (measured).	Runs in the isolated world; page scripts don't see it (measured). Use `config` for identity values instead of init-script patches.
Console events, routing, screenshots, tracing	Work.	Work.
PDF, mobile emulation	Neither: `page.pdf` is Chromium-only and Firefox has no `isMobile`.	Neither, same engine.
Threads	2 headful, 1 headless.	2 headful (virtual display), 1 headless.

As a scraper: what the site sees

	Firefox	Camoufox
TLS and HTTP/2	Firefox's: JA4 `t13d1617h2_…`, Firefox HTTP/2 SETTINGS and header order.	Identical — same NSS stack, same JA4, same HTTP/2 fingerprint (measured). Whatever OS the persona claims, real Firefox sends exactly this on every OS, so it never contradicts the user agent.
`navigator.webdriver`	`true` (measured). Playwright's Firefox build announces automation; bot.sannysoft.com marks "WebDriver" red.	`false` (measured).
Who it says it is	Firefox 150 on Linux x86_64, `navigator.languages` empty, 1280×720 screen, the server's 64 cores, `llvmpipe` (Mesa) software renderer, 0 plugins, no PDF viewer — a Linux server running an automated browser, in plain sight.	Firefox 152 on a generated desktop (macOS in this run: `MacIntel`, 1440×900×30-bit screen, "Apple M1, or similar" GPU, 2 cores, 5 plugins, PDF viewer) — a consumer machine, different each launch unless you pin `os`/`fingerprint`.
Locale and time	`UTC`, no languages. Set `locale` and `timezoneId` in `newContext` yourself.	`geoip` matched the proxy exit: this run's exit was in Morocco and the browser reported `Africa/Casablanca` and `tzm-MA` without any code (Spain and Brazil in other runs).
Canvas	Deterministic for the build.	Different hash from Firefox (measured) — the persona's fonts and rendering, consistent within a session.
bot.sannysoft.com	4 of 57 checks red: WebDriver, "Chrome (New)", two plugin checks.	1 red: "Chrome (New)" — it is Firefox and says so. (The page rendered fewer rows in Camoufox before our 4-second cut-off; see raw output.)
The limit	Honest Linux automation: fine for rendering tests, screenshots and sites that don't care; the `webdriver` flag alone fails most bot checks.	Cannot be Chromium: sites that require Chrome-only behaviour or the `Google Chrome` client-hint brand see Firefox. Firefox-blocking sites block it too.

Which to pick

Firefox when you want Mozilla's engine as-is — cross-engine rendering checks, Gecko-specific bugs, a second opinion next to Chromium — and nobody is scoring the visitor. It is the cheaper mental model: what you set is what the page sees.
Camoufox whenever the site scores visitors: webdriver off, a consumer-hardware story, locale and clock that match the proxy exit, and the whole persona generated for you. Budget for the isolated-world rule (main_world_eval) and for Firefox-only behaviour.
Neither for Chromium-only sites — use Chrome or Patchright; see Camoufox vs Patchright for that choice.

Measured on the fleet (2026-10-05)

One headful launch of each through the same rotating residential proxy. Camoufox's persona (OS, screen, GPU, cores, locale, timezone) is regenerated every launch; Firefox's values are the server's. navigator.languages came back empty for Firefox over the Playwright connection.

Launch and cost

Single run; timings depend on the proxy and on fleet load.

	Firefox	Camoufox
Launch body	{"headless":false}	{"headless":false,"main_world_eval":true}
Threads used	2 (linux_headful)	2 (linux_headful)
Browser version	150.0.2	152.0.4-beta.30
Launch request → browser ready	2.8 s	5.8 s
Playwright connect	1.4 s	0.0 s
Load example.com	0.9 s	0.8 s
Load tls.peet.ws/api/all	0.8 s	4.7 s

What the network sees

From tls.peet.ws/api/all, requested by the browser itself. JA3 hashes change between runs of the same build (GREASE), so compare JA4 and the HTTP/2 fingerprint.

	Firefox	Camoufox
HTTP version	h2	h2
JA4	t13d1617h2_86a278354501_3cbfd9057e0d	t13d1617h2_86a278354501_3cbfd9057e0d
Peetprint hash	fd4547eeb41f073156b7bc8125a79a3c	fd4547eeb41f073156b7bc8125a79a3c
Akamai HTTP/2 fingerprint	1:65536;2:0;4:131072;5:16384\|12517377\|0\|m,p,a,s	1:65536;2:0;4:131072;5:16384\|12517377\|0\|m,p,a,s
Cipher suites / extensions	16 / 17	16 / 17
Header order (first 12)	method, path, authority, scheme, user-agent, accept, accept-language, accept-encoding, upgrade-insecure-requests, sec-fetch-dest, sec-fetch-mode, sec-fetch-site	method, path, authority, scheme, user-agent, accept, accept-language, accept-encoding, upgrade-insecure-requests, sec-fetch-dest, sec-fetch-mode, sec-fetch-site

What page scripts see

Read with page.evaluate on example.com. Cores and memory are the server's and vary between fleet nodes.

	Firefox	Camoufox
navigator.userAgent	Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.0	Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.0
navigator.platform / vendor	Linux x86_64 / ""	MacIntel / ""
Languages	—	tzm-MA, tzm
Timezone / locale	UTC / en-GB	Africa/Casablanca / en-GB
Screen (w×h×availW×availH×depth)	1280x720x1280x720x24	1440x900x1440x900x30
Window outer / inner / DPR	1280x720 / 1280x720 / 1	1440x900 / 1280x720 / 1
hardwareConcurrency / deviceMemory	64 / —	2 / —
WebGL vendor	Mesa	Apple
WebGL renderer	llvmpipe, or similar	Apple M1, or similar
WebGL version	WebGL 2.0	WebGL 2.0
WebGPU (navigator.gpu)	no	no
Canvas hash	71eb6917	384a49dd
navigator.webdriver	yes	no
window.chrome / navigator.connection	no / no	no / no
Plugins / PDF viewer	0 / no	5 / yes
Notification.permission / permissions.query	default / prompt	default / prompt

Web platform features

Presence probes; a user agent that claims one version while exposing another's features is a detectable inconsistency.

	Firefox	Camoufox
`Iterator.prototype.includes` (new in Chrome 154)	no	no
`FontFace.width` (new in Chrome 154)	no	no
CSS `text-decoration-inset` (new in Chrome 154)	yes	yes
`Iterator.prototype.join` (Chrome 153)	no	no
`Iterator.zip` (Chrome 153)	yes	yes
CSS `scroll-axis-lock` (Chrome 153)	no	no
`<camera>` element (Chrome 153)	no	no
`document.requestStorageAccessFor` (deprecated in 153)	no	no
Topics API (`document.browsingTopics`)	no	no
Protected Audience (`navigator.joinAdInterestGroup`)	no	no
Shared Storage (`window.sharedStorage`)	no	no
Attribution Reporting (`window.attributionReporting`)	no	no
Private Aggregation	no	no
WebHID (`navigator.hid`)	no	no
CSS `margin-trim` (Chrome 155)	no	no
CSS `text-decoration-skip-spaces` (Chrome 155)	no	no
CSS `corner` shorthand (Chrome 155)	no	no
CSS `symbols()` (Chrome 155)	yes	yes
`Element.streamAppendHTML` (Chrome 155)	no	no
`WebTransport.reliability` (Chrome 155)	yes	yes
`window.maximize()` — Additional Windowing Controls (Chrome 155)	no	no
Canvas `srgb-linear` colour space (Chrome 155)	no	no
Permission policy `media-playback-while-not-visible` (Chrome 155)	no	no

bot.sannysoft.com

The classic headless-detection test page; what it marks red.

	Firefox	Camoufox
Checks / failed	57 / 4	37 / 1
Failed checks	WebDriver (New), Chrome (New), Plugins Length (Old), Plugins is of type PluginArray	Chrome (New)

A plain-HTTP URL (http://ip-api.com/json)

Chrome 154 warns before loading insecure HTTP by default — does that reach an automated session?

	Firefox	Camoufox
Final URL	http://ip-api.com/json/?fields=status	http://ip-api.com/json/?fields=status
HTTP status	200	200
Content loaded / warning page first	yes / no	yes / no

Playwright over the remote connection

Which client features work on this side.

	Firefox	Camoufox
page.evaluate runs in the page's own world	yes	no
`main_world_eval` option (`mw:` prefix)	—	yes
addInitScript visible to page scripts	yes	no
Console events	yes	yes
Request interception (page.route)	yes	yes
Screenshot	yes	yes
PDF	no — Error: page.pdf: PDF generation is only supported for Headless Chromium	no — Error: page.pdf: PDF generation is only supported for Headless Chromium
Mobile device emulation	no — Error: browser.newContext: options.isMobile is not supported in Firefox	no — Error: browser.newContext: options.isMobile is not supported in Firefox
Tracing	yes	yes

Rows where the two sides differ are highlighted. IP addresses are replaced with placeholders (203.0.113.x). The probe is compare/probe.mjs in our repository; the raw result is below.

Raw output

{
  "ran_at": "2026-10-05T21:03:08.264Z",
  "sides": [
    {
      "label": "Firefox",
      "engine": "firefox",
      "body": {
        "headless": false
      },
      "launch": {
        "browser": "firefox",
        "resource_class": "linux_headful",
        "weight": 2,
        "launch_ms": 2796,
        "connect_ms": 1403,
        "example_ms": 922,
        "peet_ms": 823
      },
      "network": {
        "http_version": "h2",
        "ja4": "t13d1617h2_86a278354501_3cbfd9057e0d",
        "ja3_hash": "6447ab086255d194909d4013b1a89e87",
        "peetprint_hash": "fd4547eeb41f073156b7bc8125a79a3c",
        "ciphers": 16,
        "extensions": 17,
        "akamai_h2": "1:65536;2:0;4:131072;5:16384|12517377|0|m,p,a,s",
        "akamai_h2_hash": "6ea73faa8fc5aac76bded7bd238f6433",
        "header_order": [
          "method",
          "path",
          "authority",
          "scheme",
          "user-agent",
          "accept",
          "accept-language",
          "accept-encoding",
          "upgrade-insecure-requests",
          "sec-fetch-dest",
          "sec-fetch-mode",
          "sec-fetch-site"
        ]
      },
      "page": {
        "user_agent": "Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.0",
        "platform": "Linux x86_64",
        "vendor": "",
        "languages": [
          "undefined"
        ],
        "hardware_concurrency": 64,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": true,
        "plugins": 0,
        "pdf_viewer": false,
        "ua_data": null,
        "screen": "1280x720x1280x720x24",
        "window": {
          "outer": "1280x720",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "UTC",
        "locale": "en-GB",
        "webgl": {
          "vendor": "Mesa",
          "renderer": "llvmpipe, or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "71eb6917",
        "webgpu": false,
        "chrome_object": false,
        "chrome_runtime": false,
        "notification_permission": "default",
        "notification_query": "prompt",
        "has_focus": true,
        "connection_api": false,
        "stack_read_by_debugger": false,
        "features": {
          "iterator_includes": false,
          "iterator_join": false,
          "iterator_zip": true,
          "fontface_width": false,
          "css_text_decoration_inset": true,
          "css_scroll_axis_lock": false,
          "websocket_options_bag": null,
          "camera_element": false,
          "topics_api": false,
          "protected_audience": false,
          "shared_storage": false,
          "attribution_reporting": false,
          "request_storage_access_for": false,
          "webhid": false,
          "private_aggregation": false,
          "css_margin_trim": false,
          "css_text_decoration_skip_spaces": false,
          "css_corner_shorthand": false,
          "css_symbols": true,
          "stream_append_html": false,
          "webtransport_reliability": true,
          "window_maximize": false,
          "media_display_state": true,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false
        }
      },
      "page_main_world": null,
      "sannysoft": {
        "checks": 57,
        "failed": 4,
        "failed_names": [
          "WebDriver (New)",
          "Chrome (New)",
          "Plugins Length (Old)",
          "Plugins is of type PluginArray"
        ],
        "passed": 26
      },
      "plain_http": {
        "final_url": "http://ip-api.com/json/?fields=status",
        "status": 200,
        "title": "",
        "loaded": true,
        "warning_page": false,
        "page_text": "{\"status\":\"success\"}"
      },
      "playwright": {
        "evaluate_in_main_world": true,
        "console_events": true,
        "init_script": true,
        "route": true,
        "screenshot": true,
        "pdf": false,
        "pdf_error": "Error: page.pdf: PDF generation is only supported for Headless Chromium",
        "mobile_emulation": false,
        "mobile_emulation_error": "Error: browser.newContext: options.isMobile is not supported in Firefox",
        "tracing": true
      },
      "browser_version": "150.0.2"
    },
    {
      "label": "Camoufox",
      "engine": "camoufox",
      "body": {
        "headless": false,
        "main_world_eval": true
      },
      "launch": {
        "browser": "camoufox",
        "resource_class": "linux_headful",
        "weight": 2,
        "launch_ms": 5833,
        "connect_ms": 28,
        "example_ms": 758,
        "peet_ms": 4685
      },
      "network": {
        "http_version": "h2",
        "ja4": "t13d1617h2_86a278354501_3cbfd9057e0d",
        "ja3_hash": "6447ab086255d194909d4013b1a89e87",
        "peetprint_hash": "fd4547eeb41f073156b7bc8125a79a3c",
        "ciphers": 16,
        "extensions": 17,
        "akamai_h2": "1:65536;2:0;4:131072;5:16384|12517377|0|m,p,a,s",
        "akamai_h2_hash": "6ea73faa8fc5aac76bded7bd238f6433",
        "header_order": [
          "method",
          "path",
          "authority",
          "scheme",
          "user-agent",
          "accept",
          "accept-language",
          "accept-encoding",
          "upgrade-insecure-requests",
          "sec-fetch-dest",
          "sec-fetch-mode",
          "sec-fetch-site"
        ]
      },
      "page": {
        "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.0",
        "platform": "MacIntel",
        "vendor": "",
        "languages": [
          "tzm-MA",
          "tzm"
        ],
        "hardware_concurrency": 2,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "1440x900x1440x900x30",
        "window": {
          "outer": "1440x900",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Africa/Casablanca",
        "locale": "en-GB",
        "webgl": {
          "vendor": "Apple",
          "renderer": "Apple M1, or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "384a49dd",
        "webgpu": false,
        "chrome_object": false,
        "chrome_runtime": false,
        "notification_permission": "default",
        "notification_query": "prompt",
        "has_focus": true,
        "connection_api": false,
        "stack_read_by_debugger": false,
        "features": {
          "iterator_includes": false,
          "iterator_join": false,
          "iterator_zip": true,
          "fontface_width": false,
          "css_text_decoration_inset": true,
          "css_scroll_axis_lock": false,
          "websocket_options_bag": null,
          "camera_element": false,
          "topics_api": false,
          "protected_audience": false,
          "shared_storage": false,
          "attribution_reporting": false,
          "request_storage_access_for": false,
          "webhid": false,
          "private_aggregation": false,
          "css_margin_trim": false,
          "css_text_decoration_skip_spaces": false,
          "css_corner_shorthand": false,
          "css_symbols": true,
          "stream_append_html": false,
          "webtransport_reliability": true,
          "window_maximize": false,
          "media_display_state": true,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false
        }
      },
      "page_main_world": {
        "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.0",
        "platform": "MacIntel",
        "vendor": "",
        "languages": [
          "tzm-MA",
          "tzm"
        ],
        "hardware_concurrency": 2,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "1440x900x1440x900x30",
        "window": {
          "outer": "1440x900",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Africa/Casablanca",
        "locale": "en-GB",
        "webgl": {
          "vendor": "Apple",
          "renderer": "Apple M1, or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "384a49dd",
        "webgpu": false,
        "chrome_object": false,
        "chrome_runtime": false,
        "notification_permission": "default",
        "notification_query": "prompt",
        "has_focus": true,
        "connection_api": false,
        "stack_read_by_debugger": false,
        "features": {
          "iterator_includes": false,
          "iterator_join": false,
          "iterator_zip": true,
          "fontface_width": false,
          "css_text_decoration_inset": true,
          "css_scroll_axis_lock": false,
          "websocket_options_bag": null,
          "camera_element": false,
          "topics_api": false,
          "protected_audience": false,
          "shared_storage": false,
          "attribution_reporting": false,
          "request_storage_access_for": false,
          "webhid": false,
          "private_aggregation": false,
          "css_margin_trim": false,
          "css_text_decoration_skip_spaces": false,
          "css_corner_shorthand": false,
          "css_symbols": true,
          "stream_append_html": false,
          "webtransport_reliability": true,
          "window_maximize": false,
          "media_display_state": true,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false
        }
      },
      "sannysoft": {
        "checks": 37,
        "failed": 1,
        "failed_names": [
          "Chrome (New)"
        ],
        "passed": 9
      },
      "plain_http": {
        "final_url": "http://ip-api.com/json/?fields=status",
        "status": 200,
        "title": "",
        "loaded": true,
        "warning_page": false,
        "page_text": "{\"status\":\"success\"}"
      },
      "playwright": {
        "evaluate_in_main_world": false,
        "console_events": true,
        "init_script": false,
        "route": true,
        "screenshot": true,
        "pdf": false,
        "pdf_error": "Error: page.pdf: PDF generation is only supported for Headless Chromium",
        "mobile_emulation": false,
        "mobile_emulation_error": "Error: browser.newContext: options.isMobile is not supported in Firefox",
        "tracing": true,
        "main_world_eval_option": true
      },
      "browser_version": "152.0.4-beta.30"
    }
  ]
}

Bottom line

Camoufox is Firefox with one job added: to make every identity question agree with a believable machine and with the proxy. It keeps Firefox's network fingerprint — which is a feature, since Firefox's TLS is the same on every OS — and replaces everything above it.

If you were about to patch stock Firefox with newContext options and init scripts to hide webdriver, fix the GPU string and set a timezone, that work is what Camoufox already did, inside the engine where a page can't inspect it.