Chat with your PDFs and docs.
See visual chunks from your sources beside the answer. Open the source page to check the figure, table, or diagram yourself.
The Keyline app: Document Intelligence, by Helpfeel. Public Preview access by request.Built by the team behind Helpfeel. Trusted by 625+ companies for reliable self-service.
Most AI ingests a PDF. Keyline reads it.
Standard OCR flattens a diagram into a string of characters with no meaning left in it. A parts compatibility matrix becomes gibberish. A wiring diagram becomes noise. Keyline indexes the document in its original visual format, so figures, tables, and layout keep the relationships that make them useful in the first place.
It reads figures and tables, not just text.
A compatibility matrix, an assembly diagram, a dimensional tolerance table: these are not extra credit, they are the knowledge. Keyline preserves them and answers from them directly.
It shows you exactly where the answer came from.
Check the answer against its source page and visual chunks, including relevant figures and tables shown inline.
Find Documents
Interprets what you are asking and surfaces the right document and section, even when you do not know which manual to open.
With Helpfeel PDF Search, Fujimak made 370 pages of manuals searchable for 218 service engineers across 70 locations. Monthly access grew 5x and inquiry handling time dropped by about 80 percent. These are not Keyline results.
“Previously, finding information meant flipping through thick PDF manuals. Now, just search first, is becoming habitual.”Karita, Service Department, Fujimak Corporation
Three ways in, one verified answer.
Find Documents
Interprets what you are asking and surfaces the right document and section, even when you do not know which manual to open.
Best for: Which spec sheet covers this part?
Read & Interpret
Deep-reads a specific document, or a set of them, and answers questions that require cross-referencing and judgment, not just lookup.
Best for: Does this filter meet a MERV 14 rating?
File Search
Finds a specific file by name, metadata, or content keyword when you already know roughly what you are looking for.
Best for: Where is the 2024 revision of this manual?
Ask a follow-up, request a translation, or ask Keyline to turn an answer into something you can hand to a colleague. The conversation stays attached to the source, and every question and answer is logged so a team builds shared knowledge instead of re-asking the same thing.
Compare tools on your technical documents.
Compare one job: finding an answer in a technical document and checking it against the source figure or table. These are buying criteria, not head-to-head test results.
Official sources reviewed October 8, 2026. Features and limits depend on the plan and can change.
Keyline and NotebookLM / Gemini Notebook
| Dimension | Keyline | NotebookLM / Gemini Notebook |
|---|---|---|
| Capacity | Confirm current preview limits for your library | Sources per notebook depend on plan; check Google's current limits |
| Outputs to evaluate | Answers with source pages and visual chunks | Chat, reports, audio overviews, mind maps, and other study formats |
| Your document test | Check the answer against the cited figure or table | Check the answer against the same figure or table |
| Team use | Confirm the workflow and access settings during the preview | Advanced sharing is available to paid users; plan terms vary |
Consider Google's notebook when you need several research or study formats. Evaluate Keyline when you need answers with visual chunks from technical documents. Check current plan limits rather than assuming one limit applies to every plan.
Keyline and Microsoft 365 Copilot
| Dimension | Keyline | Microsoft 365 Copilot |
|---|---|---|
| Built for | Answers from technical documents with visual chunks | Document tasks across Microsoft 365 apps and Copilot Chat |
| File support | See Keyline pricing for supported file types and current limits | PDF is supported for several tasks; support varies by app and task |
| Your document test | Check the answer against the cited figure or table | Check the answer against the same figure or table |
| Setup | Apply for Public Preview access to the app and API | Check the selected app, task, and subscription before testing |
Evaluate Microsoft 365 Copilot first if your document work already happens in Microsoft 365. Evaluate Keyline when you want a separate document-answer app or retrieval API. File support alone does not establish answer quality for either product.
Use the same document and question
Upload the same public technical PDF to each tool. Ask one question whose answer is in a table or diagram. Record the product, plan, date, answer, and citation. Check each answer against the original page.
We have not published a controlled comparison here. A correct answer on one document does not establish accuracy on your whole library.
Check Keyline pricing and preview limitsBuilt for the person who actually opens the PDF.
You are guessing at which manual has the answer, or waiting on the one person who knows.
Keyline shows the source page and relevant visual chunks beside the answer.
Your team relies on one product specialist to find answers across manuals.
Team members can check source-linked answers against the same approved documents.
You are the one who has to sign off on a new tool without a six-week procurement cycle.
Keyline is document-first by design: point it at your own PDFs and see it working on your own documents before you commit.
Start where you are.
Stage 1: Land with Keyline.
Point it at the manuals, spec sheets, or regulatory PDFs your team already has. No integration project, no procurement committee. Solve one immediate, visible pain: your team stops spending hours flipping through manuals.
Stage 2: Prove it internally.
Usage and question logs build a track record your team can point to. Access volume climbing, and fewer interruptions to your one product expert, are the kind of proof that gets a renewal signed off without a fight.
Stage 3: Bring it to your customers.
If your team loves searching your own documentation, the same verified reading engine can power self-service for the customers asking those questions too.
Built for the tools you already use, including your AI agent.
PDF, Word, Excel, PowerPoint, PNG, and JPEG. Point Keyline at the documents your team already has.
Start on your own documents.
Book a demo and we point Keyline at your PDFs. Indexing is automatic, so you see it working on your real documents, not a canned demo set.
Bring your own agent.
Keyline works alongside Claude, Codex, and the other AI agents your team already runs: they reach the same libraries through the Keyline API.
The same engine, as an API.
Technical teams can skip the app entirely and call the Keyline API from their own tools, so a verified answer appears in the interface their users already open.
SharePoint, and growing.
SharePoint integration is live today, with more connectors on the roadmap.
Related Helpfeel customer results.
These teams used Helpfeel PDF Search. Their results do not measure Keyline.
Fujimak Corporation
With Helpfeel PDF Search, 370 pages of commercial kitchen equipment manuals became searchable. Monthly access grew from about 200 to about 1,000, and inquiry handling workload dropped by roughly 80 percent within the first year. This is not a Keyline result.
siroca
With Helpfeel PDF Search, this kitchen and household appliance manufacturer migrated 500 to 600 pages of support content in about a month. This is not a Keyline result.
In an early demo, we pointed Keyline at an actual product PDF from a 90-year HVAC filter manufacturer and asked whether a specific filter met a MERV 14 rating. Keyline found the right page and answered with the diagram attached, on the spot.
Part of the Helpfeel platform. 625+ companies trust Helpfeel for reliable self-service.
See what Keyline finds in your own documents.
Book a demo and we will point Keyline at a PDF your team normally has to search by hand.
Built by the team behind Helpfeel. 625+ companies. 99% renewal.