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When you send a document to Blink PDF, your Markdown input is processed entirely in memory and discarded the moment your PDF is returned — it is never written to a database, logged to disk, or retained beyond the lifecycle of a single API request. Rendered outputs — the PDF, any images you staged, and download links — are retained for at most 24 hours to serve delivery and caching, then purged automatically.

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What zero-retention means

“Your Markdown input is processed in memory and never stored. Outputs live 24 hours at most. Nothing is ever used to train models.”
The input side is a hard architectural guarantee, not a configurable policy. The rendering pipeline is stateless with respect to your document content:
  1. Your request arrives and is held in memory for the duration of the render.
  2. The PDF is generated and streamed back to you.
  3. The request payload — all Markdown content, metadata, and intermediate document state — is immediately purged from memory.
No background job, no async flush, no eventual-consistency delay retains your input. When the response closes, your submitted document is gone from memory.
“Purged immediately” applies to your input: Blink PDF does not use write-ahead logs, render queues, or persistent buffers that retain the Markdown you send after the response. Rendered output bytes and staged assets are a separate, time-boxed store described below.

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What is NOT stored

Your submitted document content is never written to a persistent store:
  • Markdown content — the document text you send in the request body
  • PDF metadata — titles, authors, and custom fields you pass in the metadata field
  • Document structure — headings, tables, and the intermediate parse tree
  • Remote images — images fetched from http(s):// URLs during rendering are held in memory only and discarded after use, unless you opt into pinRemoteImages (see the note below)

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What IS stored (for at most 24 hours)

To serve delivery, caching, and reusable assets, Blink PDF keeps a small, time-boxed set of data — all of it purged automatically after a flat 24-hour window on every plan: Usage counters record that a render happened and how large it was — not what was in it. Your document content never touches the billing subsystem. Staged assets are scoped per credential and addressed by their content hash; the stored asset lives up to 24 hours.
Opt-in image pinning. pinRemoteImages is false by default — remote images are discarded after use. When you set it to true, only the referenced remote image bytes are retained, for up to 24 hours, scoped per credential and addressed by content hash. Your Markdown, metadata, and document structure are still never persisted, and the validate path never pins.
The MCP download flow. Because an AI agent can’t receive raw PDF bytes, the Blink PDF MCP server returns a signed download link (GET /d/:token) to the rendered output. That link and its stored object follow the same flat 24-hour window as every other output. Your Markdown input is never persisted in either the REST or MCP path.
Need a stricter posture — no output retention at all, or deployment inside your own environment? Enterprise plans run on dedicated infrastructure with data isolation, a zero-retention output option, and on-premise / VPC deployment. Contact sales.

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Zero model training

Your data is never used to train, fine-tune, or evaluate any machine learning model — Blink PDF’s own or any third party’s. The rendering engine is deterministic software, not a learned model, and it has no feedback loop that ingests document content.
If you work in a regulated industry and need to document these guarantees for an audit, the retention policy is stated in the Blink PDF Terms of Service. A signed Data Processing Addendum (DPA) is on the roadmap — email [email protected] for the current status and timeline.

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Why this matters for regulated industries

Industries with strict data-handling requirements — legal, medical, financial services, government — often cannot send document content to third-party services that log or store it, even temporarily. Zero-retention removes that blocker:
  • Legal — draft contracts, briefs, and privileged correspondence can be rendered without leaving your control boundary.
  • Medical — patient-facing documents (discharge summaries, lab results) containing sensitive personal information can be generated without that input being written to disk or logged.
  • Finance — trade confirmations, account statements, and KYC documents can be formatted as PDFs without exposing sensitive figures to a third-party data store.
Formal certifications — SOC 2 Type II and a signed DPA — are on the Blink PDF roadmap, not yet available. If either is a hard requirement for your procurement process, contact the team for the current status and timeline. For workloads that need a stricter boundary today, Enterprise offers dedicated infrastructure and on-premise / VPC deployment.

Markdown Rendering

See how the stateless in-memory rendering pipeline works end to end.

Accessibility

Learn about PDF/UA-1 compliance, Unicode support, and color emoji.