Deep Research tools have moved fast. Many now ship dozens of connectors and MCP integrations, and can produce long reports in minutes. Using them in real work, though, the same gaps keep showing up.
Where today's Deep Research tools fall short
1. Long-tail and private sources are still hard to connect
Connectors and MCP look abundant on paper. In practice, a huge share of useful knowledge lives on long-tail sites and in private data sources — internal docs, niche portals, authenticated apps — that never appear in the default catalog.
Integrating those sources usually means building a custom MCP server, handling auth, and maintaining it as APIs change. For most teams, that cost is high enough that private knowledge never enters the research loop at all.
2. Search is wide on the surface, shallow in the evidence
Many tools search more sources than before, but still not widely enough for serious research. Worse, most of them only read summaries or snippets. They rarely open the full page and work through the actual content.
When the agent never reads the page, the "evidence" behind an answer is incomplete. Conclusions can sound confident while resting on headlines, abstracts, or search snippets — not on what the source actually says.
3. Citations point to pages, not to the words that matter
Even when a report includes references, they often stop at a link and a page title. You can open the source, but you still have to hunt for the sentence that supposedly supports the claim.
Without the cited text itself, verification is slow and easy to fake. A citation that cannot show the exact passage is only half a citation.
SpanSearch exists to close these gaps
We built SpanSearch around a simple idea: research should search the sources you choose, read what those sources actually say, and show the exact text behind every important claim.
How SpanSearch does it
Bring any source into the loop — without a custom MCP project.
SpanSearch combines built-in connectors with custom data sources you define. With the browser connector, you can add sites and apps you already use in one click, including long-tail and private sources that standard catalogs miss. You decide what the agent may access before research starts.
Search broadly, then read deeply.
SpanSearch does not stop at snippets. It covers many sources for breadth, then opens full pages and reads the content for depth — so answers are grounded in what was actually read, not guessed from summaries.
Cite the exact text, not just the URL.
Every insight links back to its origin. Instead of only naming a page, SpanSearch surfaces the specific passage that supports the claim, so you can verify a sentence in seconds.
Keep research local-first.
Your research data stays on your device. You get deeper search and precise writing without giving up control of the material you care about most.
Who it is for
If your work depends on internal and private knowledge, or claims you must be able to defend, shallow Deep Research is not enough. SpanSearch is for people who need reports that search the sources you choose, read them at full depth, and stay checkable line by line.
Ready to try it? Get started for free — no credit card required.