[Compare](https://cdpfleet.com/docs/compare) / browsers

# WebKit vs Chromium

Playwright's WebKit 26.4 claims a Mac in its user agent but reports Linux, sets navigator.webdriver and speaks HTTP/1.1 through a proxy. Where it beats Chromium (CSS, testing), and why it is not an iPhone's browser.

[WebKit](https://cdpfleet.com/docs/browsers/webkit) [Chromium](https://cdpfleet.com/docs/browsers/chromium)

[WebKit](https://cdpfleet.com/docs/browsers/webkit) on the fleet is the WebKit build that ships with Playwright — the engine behind Apple's browser, compiled for Linux — at version **26.4**. [Chromium](https://cdpfleet.com/docs/browsers/chromium) is Playwright's Chromium build, **148.0.7778.96**. Both are measured headful, the same night, through the same proxy. Two questions: what is different for a page that renders in each, and what does a site see — in particular when you put WebKit behind an iPhone device descriptor to stand in for an iPhone?

## As a developer: driving them

|  | WebKit | Chromium |
| --- | --- | --- |
| Version on the fleet | WebKit **26.4** (Playwright's build), one version. | Chromium **148.0.7778.96** (Playwright's build), one version. |
| Launch options | `screen_size`, `keep_alive`, `start_url` (headful), `profile`, `record`. **No `cdp` and no `live_view`**: headful sessions get a VNC live link, but WebKit ignores the viewer's clicks. | The same plus `cdp` (`connectOverCDP`, Puppeteer) and `live_view` (headless live view). |
| Playwright features | Main-world evaluate, console events, init scripts, routing, screenshots, device emulation and tracing work. **`page.pdf()` fails:** "PDF generation is only supported for Headless Chromium" (measured). | All of them, `page.pdf()` included — headful too (measured). |
| Web platform (newer CSS and APIs) | Has CSS `margin-trim`, CSS `random()`, `FontFace` width and WebTransport `reliability` — **none of which Chromium 148 has** (measured). | Has WebGPU, WebHID, the Topics API, Fenced Frames, Shared Storage, Protected Audience, Compression Dictionary transport and `requestStorageAccessFor` — **none of which WebKit has** (measured). |
| Cookies | Refuses every cookie on a domain listed in the Public Suffix List (httpbin.org is one) — [case 57](https://cdpfleet.com/docs/cases/inspect-and-edit-the-cookie-jar). | Keeps host-only cookies there. |
| Fulfilled responses | HTML served from `page.route` with only `charset=utf-8` in its Content-Type is decoded as Latin-1 — [case 48](https://cdpfleet.com/docs/cases/mock-api-responses). | Decoded as UTF-8. |

## As a scraper: what the site sees

|  | WebKit | Chromium |
| --- | --- | --- |
| User agent | `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.15` — **a Mac**, while `navigator.platform` says **`Linux x86_64`**. | `Mozilla/5.0 (X11; Linux x86_64) … Chrome/148.0.0.0 Safari/537.36` and `navigator.platform` `Linux x86_64` — they agree. |
| Client hints | None: no `navigator.userAgentData`. | Brands `Chromium 148`, `Not/A)Brand 99`; platform Linux, desktop. |
| `navigator.webdriver` | **`true`**. | `false`. |
| TLS | JA4 **`t13d2914h1_723694b0fccc_067a5f92fbdb`**: 29 ciphers, 14 extensions, and ALPN offers HTTP/1.1 only. | JA4 `t13d1516h2_8daaf6152771_d8a2da3f94cd`: 16 ciphers, 18 extensions, HTTP/2. |
| HTTP | **HTTP/1.1** through the proxy, so no HTTP/2 fingerprint at all ([case 01](https://cdpfleet.com/docs/cases/tls-fingerprints)). | HTTP/2 with Chromium's SETTINGS (`1:65536;2:0;4:6291456;6:262144|15663105`) and header order. |
| Vendor and WebGL | `navigator.vendor` "Apple Computer, Inc."; WebGL vendor "Apple Inc.", renderer "Apple GPU". | "Google Inc."; WebGL on SwiftShader (ANGLE, Vulkan). |
| Device signals | No `navigator.connection`, no `deviceMemory`. | `navigator.connection` and `deviceMemory` present. |
| Bot checks | bot.sannysoft.com runs 37 of its checks: 2 flags, "WebDriver (New)" and "Chrome (New)". | 57 checks: 1 flag, "WebGL Renderer" (SwiftShader on a GPU-less server). |

## WebKit with an iPhone descriptor is not an iPhone's browser

-   With Playwright's `devices['iPhone 15']` the page gets the iPhone user agent (`iPhone OS 17_5 … Version/26.4 Mobile/15E148 Safari/604.1`), a 393×659 viewport on a 393×852 screen, pixel ratio 3, `ontouchstart` and a coarse pointer (measured).
-   But `navigator.platform` stays **`Linux x86_64`**, `navigator.maxTouchPoints` is **0**, `navigator.webdriver` is **`true`**, and `navigator.standalone` doesn't exist (measured). A script that checks any of these can tell it isn't a phone.
-   The same descriptor on Chromium also keeps `Linux x86_64` and adds `navigator.vendor` "Google Inc." under that iPhone user agent, with one touch point — not a real phone either.
-   So use WebKit + a device descriptor for **layout and rendering checks**: how a page lays out, what CSS it gets, how the engine behind Apple's browser handles it. For a real iOS WebView, see [iPhone](https://cdpfleet.com/iphone).

## Which to pick

-   **Chromium** for scraping: consistent identity, no webdriver flag, HTTP/2, CDP, and PDF.
-   **WebKit** for cross-browser testing — the engine and CSS behaviour behind Apple's browser, at a layout level, including mobile viewports with a device descriptor. Don't use it where a site checks for automation: its user agent and platform disagree and it reports `navigator.webdriver`.
-   Both cost the same: two threads headful, one headless.

## Measured on the fleet (2026-10-18)

One headful launch of each through the same proxy, probed from inside a page and via tls.peet.ws.

### Launch and cost

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

|  | WebKit | Chromium |
| --- | --- | --- |
| Launch body | {"headless":false} | {"headless":false} |
| Threads used | 2 (linux\_headful) | 2 (linux\_headful) |
| Browser version | 26.4 | 148.0.7778.96 |
| Launch request → browser ready | 0.8 s | 0.7 s |
| Playwright connect | 0.1 s | 0.1 s |
| Load example.com | 6.2 s | 1.0 s |
| Load tls.peet.ws/api/all | 2.2 s | 0.9 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.

|  | WebKit | Chromium |
| --- | --- | --- |
| HTTP version | HTTP/1.1 | h2 |
| JA4 | t13d2914h1\_723694b0fccc\_067a5f92fbdb | t13d1516h2\_8daaf6152771\_d8a2da3f94cd |
| Peetprint hash | bb44ee2f537184f8584269789ab7ffee | 1d4ffe9b0e34acac0bd883fa7f79d7b5 |
| Akamai HTTP/2 fingerprint | — | 1:65536;2:0;4:6291456;6:262144|15663105|0|m,a,s,p |
| Cipher suites / extensions | 29 / 14 | 16 / 18 |
| Header order (first 12) | — | method, authority, scheme, path, sec-ch-ua, sec-ch-ua-mobile, sec-ch-ua-platform, upgrade-insecure-requests, user-agent, accept, sec-fetch-site, sec-fetch-mode |

### What page scripts see

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

|  | WebKit | Chromium |
| --- | --- | --- |
| navigator.userAgent | Mozilla/5.0 (Macintosh; Intel Mac OS X 10\_15\_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.15 | Mozilla/5.0 (X11; Linux x86\_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36 |
| UA-CH brands | — | Not/A)Brand 99 · Chromium 148 |
| UA-CH full version list | — | Not/A)Brand 99.0.0.0 · Chromium 148.0.7778.96 |
| navigator.platform / vendor | Linux x86\_64 / Apple Computer, Inc. | Linux x86\_64 / Google Inc. |
| Languages | en-US | en-US |
| Timezone / locale | UTC / en-US | UTC / en-US |
| Screen (w×h×availW×availH×depth) | 1280x720x1280x720x24 | 1280x720x1280x720x24 |
| Window outer / inner / DPR | 1280x758 / 1280x720 / 1 | 1288x805 / 1280x720 / 1 |
| hardwareConcurrency / deviceMemory | 8 / — | 64 / 32 |
| WebGL vendor | Apple Inc. | Google Inc. (Google) |
| WebGL renderer | Apple GPU | ANGLE (Google, Vulkan 1.3.0 (SwiftShader Device (Subzero) (0x0000C0DE)), SwiftShader driver) |
| WebGL version | WebGL 2.0 | WebGL 2.0 (OpenGL ES 3.0 Chromium) |
| WebGPU (navigator.gpu) | no | yes |
| Canvas hash | 25c86b3f | f5a94624 |
| navigator.webdriver | yes | no |
| window.chrome / navigator.connection | no / no | yes / yes |
| Plugins / PDF viewer | 5 / yes | 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.

|  | WebKit | Chromium |
| --- | --- | --- |
| `Iterator.prototype.includes` (new in Chrome 154) | no | no |
| `FontFace.width` (new in Chrome 154) | yes | no |
| CSS `text-decoration-inset` (Chrome 157) | no | no |
| `Iterator.prototype.join` (Chrome 153) | no | no |
| `Iterator.zip` (Chrome 153) | no | no |
| CSS `scroll-axis-lock` (Chrome 153) | no | no |
| `<camera>` element (Chrome 153) | no | no |
| `document.requestStorageAccessFor` (deprecated in 153) | no | yes |
| Topics API (`document.browsingTopics`) | no | yes |
| Protected Audience (`navigator.joinAdInterestGroup`) | no | yes |
| Shared Storage (`window.sharedStorage`) | no | yes |
| Attribution Reporting (`window.attributionReporting`) | no | no |
| Private Aggregation | no | no |
| WebHID (`navigator.hid`) | no | yes |
| CSS `margin-trim` (Chrome 155) | yes | no |
| CSS `text-decoration-skip-spaces` (Chrome 155) | no | no |
| CSS `corner` shorthand (listed for Chrome 160) | no | no |
| CSS `symbols()` (Chrome 155) | no | no |
| `Element.streamAppendHTML` (Chrome 157) | no | no |
| `WebTransport.reliability` (on stable from Chrome 157; listed for 158) | yes | no |
| `window.maximize()` — Additional Windowing Controls (Chrome 155) | no | no |
| Canvas `srgb-linear` colour space (on stable from Chrome 157) | no | no |
| Permission policy `media-playback-while-not-visible` (Chrome 155) | no | no |
| CSS `random()` (Chrome 156) | yes | no |
| CSS `scroll-snap-type: pair` (Chrome 156) | no | no |
| Fenced frames (`window.fence`) | no | yes |
| `rel=compression-dictionary` (Chrome 156 updates) | no | yes |

### bot.sannysoft.com

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

|  | WebKit | Chromium |
| --- | --- | --- |
| Checks / failed | 37 / 2 | 57 / 1 |
| Failed checks | WebDriver (New), Chrome (New) | WebGL Renderer |

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

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

|  | WebKit | Chromium |
| --- | --- | --- |
| 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.

|  | WebKit | Chromium |
| --- | --- | --- |
| page.evaluate runs in the page's own world | yes | yes |
| addInitScript visible to page scripts | yes | yes |
| 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 | yes |
| Mobile device emulation | yes | yes |
| 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": "2026-10-18T01:03:40.639Z",
  "sides": [
    {
      "label": "WebKit",
      "engine": "webkit",
      "body": {
        "headless": false
      },
      "launch": {
        "browser": "webkit",
        "resource_class": "linux_headful",
        "weight": 2,
        "launch_ms": 752,
        "connect_ms": 63,
        "example_ms": 6229,
        "peet_ms": 2246
      },
      "network": {
        "http_version": "HTTP/1.1",
        "ja4": "t13d2914h1_723694b0fccc_067a5f92fbdb",
        "ja3_hash": "4ded71be9138938d71dbef4272be7708",
        "peetprint_hash": "bb44ee2f537184f8584269789ab7ffee",
        "ciphers": 29,
        "extensions": 14,
        "header_order": null
      },
      "page": {
        "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.15",
        "platform": "Linux x86_64",
        "vendor": "Apple Computer, Inc.",
        "languages": [
          "en-US"
        ],
        "hardware_concurrency": 8,
        "device_memory": null,
        "max_touch_points": 0,
        "webdriver": true,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": null,
        "screen": "1280x720x1280x720x24",
        "window": {
          "outer": "1280x758",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "UTC",
        "locale": "en-US",
        "webgl": {
          "vendor": "Apple Inc.",
          "renderer": "Apple GPU",
          "version": "WebGL 2.0"
        },
        "canvas_hash": "25c86b3f",
        "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": false,
          "fontface_width": true,
          "css_text_decoration_inset": false,
          "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": true,
          "css_text_decoration_skip_spaces": false,
          "css_corner_shorthand": false,
          "css_symbols": false,
          "stream_append_html": false,
          "webtransport_reliability": true,
          "window_maximize": false,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": true,
          "css_scroll_snap_pair": false,
          "fenced_frames": false,
          "compression_dictionary": false
        }
      },
      "page_main_world": null,
      "sannysoft": {
        "checks": 37,
        "failed": 2,
        "failed_names": [
          "WebDriver (New)",
          "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": 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": true,
        "tracing": true
      },
      "browser_version": "26.4"
    },
    {
      "label": "Chromium",
      "engine": "chromium",
      "body": {
        "headless": false
      },
      "launch": {
        "browser": "chromium",
        "resource_class": "linux_headful",
        "weight": 2,
        "launch_ms": 740,
        "connect_ms": 53,
        "example_ms": 1000,
        "peet_ms": 868
      },
      "network": {
        "http_version": "h2",
        "ja4": "t13d1516h2_8daaf6152771_d8a2da3f94cd",
        "ja3_hash": "22d4b0372811536f39e50c3823b66c25",
        "peetprint_hash": "1d4ffe9b0e34acac0bd883fa7f79d7b5",
        "ciphers": 16,
        "extensions": 18,
        "akamai_h2": "1:65536;2:0;4:6291456;6:262144|15663105|0|m,a,s,p",
        "akamai_h2_hash": "52d84b11737d980aef856699f885ca86",
        "header_order": [
          "method",
          "authority",
          "scheme",
          "path",
          "sec-ch-ua",
          "sec-ch-ua-mobile",
          "sec-ch-ua-platform",
          "upgrade-insecure-requests",
          "user-agent",
          "accept",
          "sec-fetch-site",
          "sec-fetch-mode"
        ]
      },
      "page": {
        "user_agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36",
        "platform": "Linux x86_64",
        "vendor": "Google Inc.",
        "languages": [
          "en-US"
        ],
        "hardware_concurrency": 64,
        "device_memory": 32,
        "max_touch_points": 0,
        "webdriver": false,
        "plugins": 5,
        "pdf_viewer": true,
        "ua_data": {
          "brands": [
            {
              "brand": "Not/A)Brand",
              "version": "99"
            },
            {
              "brand": "Chromium",
              "version": "148"
            }
          ],
          "mobile": false,
          "platform": "Linux",
          "architecture": "x86",
          "bitness": "64",
          "formFactors": [
            "Desktop"
          ],
          "fullVersionList": [
            {
              "brand": "Not/A)Brand",
              "version": "99.0.0.0"
            },
            {
              "brand": "Chromium",
              "version": "148.0.7778.96"
            }
          ],
          "model": "",
          "platformVersion": "",
          "uaFullVersion": "148.0.7778.96",
          "wow64": false
        },
        "screen": "1280x720x1280x720x24",
        "window": {
          "outer": "1288x805",
          "inner": "1280x720",
          "dpr": 1
        },
        "timezone": "UTC",
        "locale": "en-US",
        "webgl": {
          "vendor": "Google Inc. (Google)",
          "renderer": "ANGLE (Google, Vulkan 1.3.0 (SwiftShader Device (Subzero) (0x0000C0DE)), SwiftShader driver)",
          "version": "WebGL 2.0 (OpenGL ES 3.0 Chromium)"
        },
        "canvas_hash": "f5a94624",
        "webgpu": true,
        "chrome_object": true,
        "chrome_runtime": false,
        "notification_permission": "default",
        "notification_query": "prompt",
        "has_focus": true,
        "connection_api": true,
        "stack_read_by_debugger": false,
        "features": {
          "iterator_includes": false,
          "iterator_join": false,
          "iterator_zip": false,
          "fontface_width": false,
          "css_text_decoration_inset": false,
          "css_scroll_axis_lock": false,
          "websocket_options_bag": null,
          "camera_element": false,
          "topics_api": true,
          "protected_audience": true,
          "shared_storage": true,
          "attribution_reporting": false,
          "request_storage_access_for": true,
          "webhid": true,
          "private_aggregation": false,
          "css_margin_trim": false,
          "css_text_decoration_skip_spaces": false,
          "css_corner_shorthand": false,
          "css_symbols": false,
          "stream_append_html": false,
          "webtransport_reliability": false,
          "window_maximize": false,
          "canvas_srgb_linear": false,
          "policy_media_playback_while_not_visible": false,
          "css_random": false,
          "css_scroll_snap_pair": false,
          "fenced_frames": true,
          "compression_dictionary": true
        }
      },
      "page_main_world": null,
      "sannysoft": {
        "checks": 57,
        "failed": 1,
        "failed_names": [
          "WebGL Renderer"
        ],
        "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": true,
        "console_events": true,
        "init_script": true,
        "route": true,
        "screenshot": true,
        "pdf": true,
        "mobile_emulation": true,
        "tracing": true
      },
      "browser_version": "148.0.7778.96"
    }
  ]
}
```

## Bottom line

WebKit and Chromium differ in everything a site can measure: TLS and HTTP version, client hints, vendor, WebGL, the webdriver flag, and a different set of newer CSS and web APIs.

WebKit is the one to check layouts against the engine behind Apple's browser; it is not a stealth browser and not an iPhone.

---
Source: https://cdpfleet.com/docs/compare/webkit-vs-chromium · Markdown: https://cdpfleet.com/docs/compare/webkit-vs-chromium.md · All docs for AI tools: https://cdpfleet.com/llms.txt