docs(session-replay): document Flutter web canvas masking

[turnipdabeets]

Changes

Documents session replay canvas masking on Flutter Web — shipped in posthog-js 1.408.0 (PostHog/posthog-js#4270) and landing in posthog-flutter via PostHog/posthog-flutter#499 + PostHog/posthog-flutter#501.

Flutter Web renders the whole app into a canvas, so DOM masking couldn't see any of it. Masking now happens inside the canvas, and these docs tell users how to turn it on:

• session-replay/_snippets/flutter-privacy.mdx — new "Masking on Flutter Web" section (the Flutter tab of the privacy page): what gets masked, the web/index.html opt-in snippet, the PostHogMaskWidget alternative, and the caveats (restart-once, pre-boot window, PostHogWidget required, blockSelector precedence, platform views, multi-view).
• session-replay/canvas-recording.mdx — corrects "there is no way to mask canvas elements right now" (no longer true) and adds a short "Masking canvas content" section for canvasCapture.maskRegionsFn.
• libraries/flutter/index.mdx — the session replay section now points at canvas masking next to the existing Canvas capture note.
• session-replay/troubleshooting.mdx — "Flutter Web canvas masking not applied" entry.

Draft until the posthog-flutter release ships: the version callout currently says Flutter SDK >= 5.34.0 — pin to the actual release number before marking ready.

Checklist

• I've read the docs and/or content style guides.
• Words are spelled using American English
• Use relative URLs for internal links
• I've checked the pages added or changed in the Vercel preview build
• If I moved a page, I added a redirect in vercel.json (no pages moved)

[github-actions]

Deploy preview

Status	Details	Updated (UTC)
🟢 Ready	View preview	Jul 30, 2026 02:51PM

[github-actions]

Vale prose linter → found 17 errors, 50 warnings, 6 suggestions in your markdown

Full report → Copy the linter results into an LLM to batch-fix issues.

Linter being weird? Update the rules!

contents/docs/libraries/flutter/index.mdx — 4 errors, 27 warnings, 5 suggestions

Line	Severity	Message	Rule
6:18	warning	Use 'GitHub' instead of 'github'.	Vale.Terms
6:37	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
97:49	suggestion	Address the reader directly. Use 'you' instead of 'the user'.	PostHogDocs.DirectAddress
99:66	suggestion	Address the reader directly. Use 'you' instead of 'the User'.	PostHogDocs.DirectAddress
99:131	suggestion	Address the reader directly. Use 'you' instead of 'the User'.	PostHogDocs.DirectAddress
113:69	warning	Avoid trivializing words. 'simply' can sound dismissive to the reader.	PostHogDocs.Trivializers
121:4	warning	'Feature flags' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
121:4	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'Feature flags' for the general industry concept.	PostHogBase.ProductNames
175:25	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
179:8	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
179:55	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
179:128	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
181:28	warning	Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept.	PostHogBase.ProductNames
181:54	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
183:4	warning	'Error tracking' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
183:4	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'Error tracking' for the general industry concept.	PostHogBase.ProductNames
185:11	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
185:52	warning	Capitalize 'Error Tracking' for PostHog's product. Use 'error tracking' for the general industry concept.	PostHogBase.ProductNames
189:12	warning	Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept.	PostHogBase.ProductNames
191:4	warning	'Session replay' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
191:4	warning	Capitalize 'Session Replay' for PostHog's product. Use 'Session replay' for the general industry concept.	PostHogBase.ProductNames
193:13	warning	Capitalize 'Session Replay' for PostHog's product. Use 'Session replay' for the general industry concept.	PostHogBase.ProductNames
195:12	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
195:65	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
195:127	warning	Avoid trivializing words. 'all you need to do' can sound dismissive to the reader.	PostHogDocs.Trivializers
200:111	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
200:276	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
250:96	suggestion	Address the reader directly. Use 'you' instead of 'the user'.	PostHogDocs.DirectAddress
251:8	suggestion	Address the reader directly. Use 'you' instead of 'the user'.	PostHogDocs.DirectAddress
328:24	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
329:23	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
330:33	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
334:3	warning	Capitalize 'Session Replay' for PostHog's product. Use 'Session replay' for the general industry concept.	PostHogBase.ProductNames
341:62	warning	Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept.	PostHogBase.ProductNames
341:100	warning	Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept.	PostHogBase.ProductNames
352:26	warning	Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept.	PostHogBase.ProductNames

contents/docs/session-replay/_snippets/flutter-privacy.mdx — 5 errors, 7 warnings, 1 suggestions

Line	Severity	Message	Rule
3:5	warning	'Masking All Texts and Images' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
16:43	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
16:100	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
30:79	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
32:17	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
59:8	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
59:72	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
61:74	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
61:88	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
62:104	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
101:13	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames
101:234	suggestion	Address the reader directly. Use 'you' instead of 'the user'.	PostHogDocs.DirectAddress
130:107	warning	'dialogs' is a possible misspelling.	PostHogBase.Spelling

contents/docs/session-replay/canvas-recording.mdx — 2 errors, 2 warnings, 0 suggestions

Line	Severity	Message	Rule
21:12	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
23:299	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
25:180	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
25:198	warning	Capitalize 'Session Replay' for PostHog's product. Use 'session replay' for the general industry concept.	PostHogBase.ProductNames

contents/docs/session-replay/troubleshooting.mdx — 6 errors, 14 warnings, 0 suggestions

Line	Severity	Message	Rule
7:4	warning	'Have a question? Ask PostHog AI' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
124:190	warning	'rrweb' is a possible misspelling.	PostHogBase.Spelling
125:163	warning	'rrweb' is a possible misspelling.	PostHogBase.Spelling
126:170	warning	'rrweb' is a possible misspelling.	PostHogBase.Spelling
174:5	warning	'Ensure your website permits PostHog CORS' heading should be in sentence case, and product names should be capitalized.	PostHogBase.SentenceCase
176:379	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
237:132	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
241:15	warning	'rrweb' is a possible misspelling.	PostHogBase.Spelling
241:34	warning	'rrweb' is a possible misspelling.	PostHogBase.Spelling
246:31	warning	'seekbar' is a possible misspelling.	PostHogBase.Spelling
247:50	warning	'renderable' is a possible misspelling.	PostHogBase.Spelling
247:69	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
257:215	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
287:110	warning	'Silverlight' is a possible misspelling.	PostHogBase.Spelling
289:172	warning	'Calendly' is a possible misspelling.	PostHogBase.Spelling
295:48	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
296:157	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
297:59	warning	Use 'PostHog' instead of 'posthog'.	Vale.Terms
297:79	error	Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash.	PostHogBase.EnDash
297:143	warning	Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept.	PostHogBase.ProductNames

[github-actions]

Bundle report

Total JS (gzip)

7.06 MiB (+0.9 KiB / +0.0%)

Eager graph (modules shipped in each entrypoint's initial chunks)

Entrypoint	Eager size	Budget	Modules
✅ app	16.34 MiB (+4.4 KiB / +0.0%)	report-only	1999

Largest modules in the app closure

Module	Size
./src/data/mcp-tools.json	914.3 KiB
css ./node_modules/.pnpm/css-loader@5.2.7_webpack@5.101.3/node_modules/css-loader/dist/cjs.js??ruleSet[1].rules[8].oneOf[1].use[1]!./node_modules/.pnpm/postcss-loader@4.3.0_postcss@8.5.6_webpack@5.101.3/node_modules/postcss-loader/dist/cjs.js??ruleSet[1].rules[8].oneOf[1].use[2]!./src/styles/global.css	736.0 KiB
./src/components/Stickers/Stickers.tsx	696.4 KiB
./node_modules/.pnpm/@radix-ui+react-icons@1.3.2_react@18.3.1/node_modules/@radix-ui/react-icons/dist/react-icons.esm.js	481.4 KiB
./node_modules/.pnpm/rehype-raw@7.0.0/node_modules/rehype-raw/lib/index.js + 29 modules	395.1 KiB
./node_modules/.pnpm/@posthog+icons@0.36.6_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/@posthog/icons/dist/posthog-icons.cjs.js	364.8 KiB
./node_modules/.pnpm/@posthog+icons@0.36.6_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/@posthog/icons/dist/posthog-icons.es.js	354.8 KiB
./src/hooks/useCustomers.tsx + 54 modules	354.8 KiB
./node_modules/.pnpm/react-markdown@8.0.7_@types+react@16.14.66_react@18.3.1/node_modules/react-markdown/lib/react-markdown.js + 88 modules	351.4 KiB
./src/components/ProductComparisonTable/index.tsx + 121 modules	282.8 KiB
./node_modules/.pnpm/cloudinary-core@2.14.0_lodash@4.17.21/node_modules/cloudinary-core/cloudinary-core.js	281.9 KiB
./src/components/SearchUI/index.tsx + 87 modules	272.1 KiB
./node_modules/.pnpm/framer-motion@10.18.0_react-dom@18.3.1_react@18.3.1__react@18.3.1/node_modules/framer-motion/dist/es/render/dom/motion.mjs + 109 modules	253.9 KiB
./node_modules/.pnpm/d3@7.9.0/node_modules/d3/src/index.js + 208 modules	247.4 KiB
./src/components/Pricing/PricingSlider/Slider.tsx + 87 modules	240.1 KiB

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Eager-graph budgets are report-only until a baseline is established. Sizes are gzip of public/**/*.js; eager size is webpack module source bytes for the modules actually shipped in the entrypoint's initial chunks (post-tree-shake).

[marandaneto]

worth mentioning the min version of the flutter sdk as well and not only the min version of the browser sdk