Compare / browsers

Camoufox vs Firefox, headless

Headless Firefox and headless Camoufox (both based on Firefox source; not affiliated with Mozilla) side by side: the headless tells a page can read, what Camoufox hides, and what its "virtual" mode costs.

Camoufox Firefox

Firefox vs Camoufox compares the two browsers headful. This page is about the cheaper mode most scrapers run: headless, where there is no display and a page has the most to notice. Firefox on the fleet is Playwright's build (150.0.2 on 2026-10-25), based on Firefox source and not affiliated with Mozilla. Camoufox is the anti-detect browser built on the same engine, also based on Firefox source and not affiliated with Mozilla (156.0.1-beta.34 on 2026-10-25, driven by the official Camoufox library). Camoufox has two headless modes: "headless": true (no display at all) and "headless": "virtual" (headful on a virtual display the page can't tell from a real one). All three were launched once through the same rotating proxy on 2026-10-25.

The headless tells, measured

	Firefox, headless	Camoufox, headless (`true` and `"virtual"`)
`navigator.webdriver`	`true`: the browser says it is automated, and bot.sannysoft.com marks "WebDriver" red.	`false` in both modes, in the page's world and in Playwright's isolated world.
Window vs viewport	Outer window = viewport = 1280×720: no browser chrome around the page, which no real desktop window has.	Outer window taller than the viewport (1280×806 and 1280×805 around a 1280×720 page), as a window with toolbars would be.
Screen	1280×720, the same as the window: the screen is the page.	A desktop screen from the persona (1920×1080 and 3440×1440 in these launches), with a taskbar-sized gap between the screen and the available height.
GPU (WebGL)	`llvmpipe` (Mesa software rendering): a server without a GPU.	A persona GPU: "Radeon HD 3200 Graphics" and "ANGLE (AMD, Radeon R9 200 Series …)" in these launches.
Cores, plugins, PDF viewer	The server's 64 cores, 0 plugins, no PDF viewer.	12 and 8 cores, 5 plugins, a PDF viewer: consumer-machine values.
Languages, timezone	`navigator.languages` gave no real list, timezone `UTC`.	Matched to the proxy exit (Spain in these launches): timezone `Europe/Madrid`, languages `es-ES` and `en-ES`.
bot.sannysoft.com	4 of 57 checks red: WebDriver, "Chrome (New)" and two plugin checks.	1 red in both modes: "Chrome (New)", because it is Firefox and says so.

What stays the same

HTTP/2: identical on all three: the same SETTINGS, window update and pseudo-header order (measured).
The engine: both are Gecko, so Chromium-only features, page.pdf and mobile emulation are missing on both (measured).
Plain-HTTP pages load on all three through the proxy (measured).

What differs beyond the tells

TLS: Camoufox 156 offers 15 cipher suites, Firefox 150 offers 16, so their JA4 (t13d1517h2_… vs t13d1617h2_…) and full TLS fingerprints differ on 2026-10-25. That is the version gap, not headless mode; see Camoufox 156.
page.evaluate and init scripts: in Camoufox they run in an isolated world that page scripts can't see; read page values with main_world_eval and the mw: prefix (measured: Firefox evaluates in the page's world, Camoufox doesn't).
Personas change per launch: the two Camoufox launches drew a Linux and a Windows persona; that difference comes from the per-launch draw, not from the headless mode. Pin os if you need one. Canvas and audio hashes are also re-drawn per launch on Camoufox and fixed on Firefox (case 66).

"virtual" vs true headless on Camoufox

	`"headless": true`	`"headless": "virtual"`
Threads	1 (headless)	2 (counted as headful)
Launch, this run	1.7 s	4.9 s
Tells measured here	The same as "virtual": webdriver false, window chrome, persona screen and GPU, 1 sannysoft flag.	The same as true headless.
When	The default for scraping: cheapest, and on these probes it showed nothing the virtual display didn't.	When a site behaves differently without a real display (rendering paths, focus, some video), or you want a recording or live view of the session.

Which to pick

Headless Firefox for engine checks and rendering tests where nobody scores the visitor. It announces itself (webdriver, a 1280×720 "screen" that equals the window, software GPU, UTC), which is honest and cheap.
Headless Camoufox for scraping where the site scores visitors: on these probes it hid every headless tell headless Firefox showed, at one thread.
Camoufox "virtual" only when you need a display: it costs two threads and launched slower, and these probes found no extra tell it removes.
For what the real protections do with each browser, see the bot-protection cases (Cloudflare, DataDome, Akamai and HUMAN) and what a page can read about your browser.

Measured on the fleet (2026-10-25)

One launch of each on 2026-10-25 through the same rotating proxy; Camoufox read through main_world_eval. Camoufox's persona (OS, screen, GPU, cores, locale, timezone) is drawn per launch, so its values differ between its two columns by chance, not by mode; Firefox's values are the server's.

Launch and cost

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

	Firefox, headless	Camoufox, headless	Camoufox, headless "virtual"
Launch body	{"headless":true}	{"headless":true,"main_world_eval":true}	{"headless":"virtual","main_world_eval":true}
Threads used	1 (linux_headless)	1 (linux_headless)	2 (linux_headful)
Browser version	150.0.2	156.0.1-beta.34	156.0.1-beta.34
Launch request → browser ready	0.9 s	1.7 s	4.9 s
Playwright connect	0.2 s	0.1 s	0.0 s
Load example.com	1.6 s	2.4 s	1.0 s
Load tls.peet.ws/api/all	1.3 s	0.9 s	1.5 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, headless	Camoufox, headless	Camoufox, headless "virtual"
HTTP version	h2	h2	h2
JA4	t13d1617h2_86a278354501_3cbfd9057e0d	t13d1517h2_8daaf6152771_3cbfd9057e0d	t13d1517h2_8daaf6152771_3cbfd9057e0d
Peetprint hash	fd4547eeb41f073156b7bc8125a79a3c	a4bbbc7e3adf3db97d276fd0adb1efc4	a4bbbc7e3adf3db97d276fd0adb1efc4
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	1:65536;2:0;4:131072;5:16384\|12517377\|0\|m,p,a,s
Cipher suites / extensions	16 / 17	15 / 17	15 / 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	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, headless	Camoufox, headless	Camoufox, headless "virtual"
navigator.userAgent	Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.0	Mozilla/5.0 (X11; Linux x86_64; rv:156.0) Gecko/20100101 Firefox/156.0	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:156.0) Gecko/20100101 Firefox/156.0
navigator.platform / vendor	Linux x86_64 / ""	Linux x86_64 / ""	Win32 / ""
Languages	—	es-ES, es	en-ES, en
Timezone / locale	UTC / en-GB	Europe/Madrid / es-ES	Europe/Madrid / en-ES
Screen (w×h×availW×availH×depth)	1280x720x1280x720x24	1920x1080x1920x1053x24	3440x1440x3440x1400x24
Window outer / inner / DPR	1280x720 / 1280x720 / 1	1280x806 / 1280x720 / 1	1280x805 / 1280x720 / 1
hardwareConcurrency / deviceMemory	64 / —	12 / —	8 / —
WebGL vendor	Mesa	AMD	Google Inc. (AMD)
WebGL renderer	llvmpipe, or similar	Radeon HD 3200 Graphics, or similar	ANGLE (AMD, Radeon R9 200 Series Direct3D11 vs_5_0 ps_5_0), or similar
WebGL version	WebGL 2.0	WebGL 2.0	WebGL 2.0
WebGPU (navigator.gpu)	no	no	no
Canvas hash	71eb6917	71bfd7ed	eb7fc317
navigator.webdriver	yes	no	no
window.chrome / navigator.connection	no / no	no / no	no / no
Plugins / PDF viewer	0 / no	5 / yes	5 / yes
Notification.permission / permissions.query	default / prompt	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, headless	Camoufox, headless	Camoufox, headless "virtual"
`Iterator.prototype.includes` (new in Chrome 154)	no	yes	yes
`FontFace.width` (new in Chrome 154)	no	yes	yes
CSS `text-decoration-inset` (new in Chrome 154)	yes	yes	yes
`Iterator.prototype.join` (Chrome 153)	no	yes	yes
`Iterator.zip` (Chrome 153)	yes	yes	yes
CSS `scroll-axis-lock` (Chrome 153)	no	no	no
`<camera>` element (Chrome 153)	no	no	no
`document.requestStorageAccessFor` (deprecated in 153)	no	no	no
Topics API (`document.browsingTopics`)	no	no	no
Protected Audience (`navigator.joinAdInterestGroup`)	no	no	no
Shared Storage (`window.sharedStorage`)	no	no	no
Attribution Reporting (`window.attributionReporting`)	no	no	no
Private Aggregation	no	no	no
WebHID (`navigator.hid`)	no	no	no
CSS `margin-trim` (Chrome 155)	no	no	no
CSS `text-decoration-skip-spaces` (Chrome 155)	no	no	no
CSS `corner` shorthand (Chrome 155)	no	no	no
CSS `symbols()` (Chrome 155)	yes	yes	yes
`Element.streamAppendHTML` (Chrome 155)	no	no	no
`WebTransport.reliability` (Chrome 155)	yes	yes	yes
`window.maximize()` — Additional Windowing Controls (Chrome 155)	no	no	no
Canvas `srgb-linear` colour space (Chrome 155)	no	no	no
Permission policy `media-playback-while-not-visible` (Chrome 155)	no	no	no
CSS `random()` (Chrome 156)	no	no	no
CSS `scroll-snap-type: pair` (Chrome 156)	no	no	no
Fenced frames (`window.fence`) — removal starts in 157	no	no	no
`rel=compression-dictionary` (Chrome 156 updates)	no	no	no

bot.sannysoft.com

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

	Firefox, headless	Camoufox, headless	Camoufox, headless "virtual"
Checks / failed	57 / 4	57 / 1	57 / 1
Failed checks	WebDriver (New), Chrome (New), Plugins Length (Old), Plugins is of type PluginArray	Chrome (New)	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, headless	Camoufox, headless	Camoufox, headless "virtual"
Final URL	http://ip-api.com/json/?fields=status	http://ip-api.com/json/?fields=status	http://ip-api.com/json/?fields=status
HTTP status	200	200	200
Content loaded / warning page first	yes / no	yes / no	yes / no

Playwright over the remote connection

Which client features work on this side.

	Firefox, headless	Camoufox, headless	Camoufox, headless "virtual"
page.evaluate runs in the page's own world	yes	no	no
`main_world_eval` option (`mw:` prefix)	—	yes	yes
addInitScript visible to page scripts	yes	no	no
Console events	yes	yes	yes
Request interception (page.route)	yes	yes	yes
Screenshot	yes	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	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	no — Error: browser.newContext: options.isMobile is not supported in Firefox
Tracing	yes	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": "2026-10-25T02:03:17.998Z",
  "sides": [
    {
      "label": "Firefox, headless",
      "engine": "firefox",
      "body": {
        "headless": true
      },
      "launch": {
        "browser": "firefox",
        "resource_class": "linux_headless",
        "weight": 1,
        "launch_ms": 938,
        "connect_ms": 152,
        "example_ms": 1553,
        "peet_ms": 1260
      },
      "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,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": 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": 27
      },
      "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, headless",
      "engine": "camoufox",
      "body": {
        "headless": true,
        "main_world_eval": true
      },
      "launch": {
        "browser": "camoufox",
        "resource_class": "linux_headless",
        "weight": 1,
        "launch_ms": 1747,
        "connect_ms": 123,
        "example_ms": 2406,
        "peet_ms": 858
      },
      "network": {
        "http_version": "h2",
        "ja4": "t13d1517h2_8daaf6152771_3cbfd9057e0d",
        "ja3_hash": "9d42e90b0225e779f03141ddcd699df2",
        "peetprint_hash": "a4bbbc7e3adf3db97d276fd0adb1efc4",
        "ciphers": 15,
        "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:156.0) Gecko/20100101 Firefox/156.0",
        "platform": "Linux x86_64",
        "vendor": "",
        "languages": [
          "es-ES",
          "es"
        ],
        "hardware_concurrency": 12,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "1920x1080x1920x1053x24",
        "window": {
          "outer": "1280x806",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Europe/Madrid",
        "locale": "es-ES",
        "webgl": {
          "vendor": "AMD",
          "renderer": "Radeon HD 3200 Graphics, or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "71bfd7ed",
        "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": true,
          "iterator_join": true,
          "iterator_zip": true,
          "fontface_width": true,
          "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,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": false
        }
      },
      "page_main_world": {
        "user_agent": "Mozilla/5.0 (X11; Linux x86_64; rv:156.0) Gecko/20100101 Firefox/156.0",
        "platform": "Linux x86_64",
        "vendor": "",
        "languages": [
          "es-ES",
          "es"
        ],
        "hardware_concurrency": 12,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "1920x1080x1920x1053x24",
        "window": {
          "outer": "1280x806",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Europe/Madrid",
        "locale": "es-ES",
        "webgl": {
          "vendor": "AMD",
          "renderer": "Radeon HD 3200 Graphics, or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "71bfd7ed",
        "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": true,
          "iterator_join": true,
          "iterator_zip": true,
          "fontface_width": true,
          "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,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": false
        }
      },
      "sannysoft": {
        "checks": 57,
        "failed": 1,
        "failed_names": [
          "Chrome (New)"
        ],
        "passed": 30
      },
      "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": "156.0.1-beta.34"
    },
    {
      "label": "Camoufox, headless \"virtual\"",
      "engine": "camoufox",
      "body": {
        "headless": "virtual",
        "main_world_eval": true
      },
      "launch": {
        "browser": "camoufox",
        "resource_class": "linux_headful",
        "weight": 2,
        "launch_ms": 4861,
        "connect_ms": 18,
        "example_ms": 1037,
        "peet_ms": 1528
      },
      "network": {
        "http_version": "h2",
        "ja4": "t13d1517h2_8daaf6152771_3cbfd9057e0d",
        "ja3_hash": "9d42e90b0225e779f03141ddcd699df2",
        "peetprint_hash": "a4bbbc7e3adf3db97d276fd0adb1efc4",
        "ciphers": 15,
        "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 (Windows NT 10.0; Win64; x64; rv:156.0) Gecko/20100101 Firefox/156.0",
        "platform": "Win32",
        "vendor": "",
        "languages": [
          "en-ES",
          "en"
        ],
        "hardware_concurrency": 8,
        "device_memory": null,
        "max_touch_points": 5,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "3440x1440x3440x1400x24",
        "window": {
          "outer": "1280x805",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Europe/Madrid",
        "locale": "en-ES",
        "webgl": {
          "vendor": "Google Inc. (AMD)",
          "renderer": "ANGLE (AMD, Radeon R9 200 Series Direct3D11 vs_5_0 ps_5_0), or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "eb7fc317",
        "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": true,
          "iterator_join": true,
          "iterator_zip": true,
          "fontface_width": true,
          "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,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": false
        }
      },
      "page_main_world": {
        "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:156.0) Gecko/20100101 Firefox/156.0",
        "platform": "Win32",
        "vendor": "",
        "languages": [
          "en-ES",
          "en"
        ],
        "hardware_concurrency": 8,
        "device_memory": null,
        "max_touch_points": 5,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "3440x1440x3440x1400x24",
        "window": {
          "outer": "1280x805",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "Europe/Madrid",
        "locale": "en-ES",
        "webgl": {
          "vendor": "Google Inc. (AMD)",
          "renderer": "ANGLE (AMD, Radeon R9 200 Series Direct3D11 vs_5_0 ps_5_0), or similar",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "eb7fc317",
        "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": true,
          "iterator_join": true,
          "iterator_zip": true,
          "fontface_width": true,
          "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,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": false
        }
      },
      "sannysoft": {
        "checks": 57,
        "failed": 1,
        "failed_names": [
          "Chrome (New)"
        ],
        "passed": 30
      },
      "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": "156.0.1-beta.34"
    }
  ]
}

Bottom line

Headless is where stock Firefox gives itself away most clearly: a window with no chrome, a screen the size of the page, a software GPU and an automation flag. Camoufox answers every one of those from the persona, in both of its headless modes.

The one thing Camoufox can't change is that it is Firefox: checks for Chrome, and sites that only serve Chromium, see Firefox either way.