What we collect

PDF911 only counts which features are used and how often. The table below is everything sent to our server, and it is generated from the code that defines the payload.

Where it goes

Events go only to /e on this same domain and are stored in the operator's Cloudflare account. No third-party analytics. IP addresses are not stored.

Never collected

File names
File contents or extracted text
Document metadata values
Exact file sizes (ranges only)
IP addresses
Cookies, cross-site identifiers, browser fingerprints

How returning visits are measured

Your browser's localStorage keeps only three values: first visit date, visit count and last activity time. Only coarse ranges derived from them (returning or not, visit-count range, days-since-first range, first-visit week) are sent. No identifier is ever created.

Storage keys: pdf911.first pdf911.count pdf911.last

Event	Field	Meaning	Values
`page_view`	`path`	Page path (no query or hash)	fixed format only
	`ref_host`	Domain of the referring site	fixed format only
	`utm_source`	Campaign source tag	fixed format only
	`utm_medium`	Campaign medium tag	fixed format only
	`utm_campaign`	Campaign name tag	fixed format only
	`device`	Device type	`mobile\|tablet\|desktop`
	`browser`	Browser family	`chrome\|safari\|firefox\|edge\|samsung\|other`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`tool_start`	`tool`	Feature used	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`opts`	Chosen options (fixed values only)	fixed format only
	`files_b`	File count range	`1\|2-5\|6-20\|21+`
	`size_b`	File size range	`<1MB\|1-10MB\|10-50MB\|50-200MB\|200MB+`
	`pages_b`	Page count range	`1\|2-10\|11-50\|51-200\|201+`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`tool_done`	`tool`	Feature used	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`duration_b`	Processing time range	`<1s\|1-5s\|5-30s\|30s+`
	`output_size_b`	Output size range	`<1MB\|1-10MB\|10-50MB\|50-200MB\|200MB+`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`tool_error`	`tool`	Feature used	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`code`	Error type	`ENCRYPTED\|CORRUPT\|UNSUPPORTED\|TOO_LARGE\|OUT_OF_MEMORY\|ENGINE_LOAD_FAILED\|INTERNAL`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`download`	`tool`	Feature used	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`format`	Saved format	`pdf\|zip\|png\|jpg`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`recipe_create`	`tools`	Features in a recipe	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`recipe_open`	`tools`	Features in a recipe	`merge\|split\|organize\|rotate\|delete\|metadata\|sanitize\|img2pdf\|pdf2img\|compress`
	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`pwa_install`	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only
`lang_switch`	`lang`	Interface language	`ko\|en`
	`country`	Country code (from Cloudflare)	fixed format only
	`site`	Production / preview / development	`prod\|preview\|dev`
	`returning`	Returning visitor or not	`true\|false`
	`visits_b`	Visit count range	`1\|2-5\|6-20\|21+`
	`days_since_first_b`	Days since first visit (range)	`0\|1-7\|8-30\|31-90\|91+`
	`cohort_week`	Week of first visit (e.g. 2026-W43)	fixed format only