X1 Search review: the business standard for email and file search

Ask a litigation support specialist or a 20-year sales veteran what they use to find email, and there's a decent chance the answer is X1 Search. It has been the business desktop-search benchmark for two decades: one fast-as-you-type interface across your files, Outlook email, attachments, and cloud sources like OneDrive and SharePoint. We ran the current release against our 1.2-million-file test library and a 9 GB Outlook mailbox to see whether it still justifies a price of around $100 per seat per year.

Who X1 Search is for

X1 is built for people whose job is buried in correspondence: lawyers, salespeople, project managers, consultants, anyone with a six-figure email count and contracts scattered across local folders, OneDrive and SharePoint. If you bill by the hour, the arithmetic is straightforward — a tool that reliably turns "where is that amendment Karen sent in 2023?" into a five-second answer pays for itself quickly.

It's overkill if you mostly search filenames (use Everything, which is free and instant), and it's hard to justify for personal use at per-seat business pricing. Home users who want indexed email-plus-file search at a lower price should read our Copernic Desktop Search review first — it covers 80% of the same ground for roughly two-thirds the cost.

Key features

Unified fast-as-you-type search

X1 indexes your files, Outlook mail, attachments, contacts, and calendar into one store, then searches all of it as you type. Each keystroke narrows the result list live — no Enter key, no waiting. Column-based filters (sender, date, file type, folder) stack on top, so a query like "fenwick agreement, from Sarah, 2024, PDF attachment" takes seconds to assemble with zero query syntax.

The preview pane that made X1 famous

This is still the best preview in desktop search. Click any result — a 60-page PDF, an Excel model, an email thread — and X1 renders it in the pane with your search terms highlighted, paged and scrollable, without ever launching Word, Excel, Acrobat or Outlook. In our testing the preview rendered almost everything we selected quickly enough that we stopped opening applications to verify matches at all. For someone triaging dozens of candidate documents an hour, this single feature is the product.

Act on results directly

X1 treats results as live objects, not just pointers. From the result list you can reply to or forward an email, open a file, open its containing folder, copy it, or drag an attachment straight into a new message. The search window becomes a working surface rather than a lookup step.

Cloud connectors: OneDrive and SharePoint

Beyond local folders and Outlook, X1 ships connectors for Microsoft 365 sources, including OneDrive and SharePoint document libraries. For organizations that have shoved everything into SharePoint and lost the ability to find any of it, this is frequently the purchase trigger. Setup requires signing into each source and choosing what to crawl; after that, cloud documents appear in the same result list as local ones.

Performance in our testing

On our Ryzen 7 / 32 GB / NVMe test machine, the initial index of the 1.2-million-file library plus the 9 GB PST took several hours — comparable to Copernic, and similarly something to schedule overnight. The index itself is on the heavier side: ours landed in the high single-digit gigabytes, and background memory use sat noticeably above lighter tools, typically a few hundred megabytes. On a modern business laptop you won't feel it; on an aging 8 GB machine you might.

Query speed is where the money goes. Once indexed, search-as-you-type across a million-plus files and a packed mailbox felt effectively instant — results visibly re-ranked with each keystroke, and even broad content terms returned in around a second in our testing. Newly saved files appeared in results within a couple of minutes on default settings; like every indexed tool, X1 has a small freshness lag, so it complements rather than replaces an instant filename tool. Our guide to searching file contents on Windows explains that indexed-versus-on-demand tradeoff in detail.

Ease of use

X1 is easy to use and busy to look at. The interface is unapologetically dense — column headers, filter rows, source tabs, a toolbar — closer to Outlook circa its power-user prime than to a minimalist launcher. Experienced business users acclimate in a day and come to love the density, because everything is one click away. People who want a single clean search box may find it intimidating at first. Setup is wizard-driven and painless for local sources; the Microsoft 365 connectors take a little more care (sign-ins, scope choices) and feel aimed at IT-assisted rollouts.

Pricing

X1 Search is sold per seat on an annual subscription. List pricing has hovered in the $96–119 per user per year range recently — call it around $100 a year — with volume and multi-year discounts for teams, and a free trial to evaluate first. Current numbers are on x1.com.

For a business, that's an easy line item if the tool gets daily use. For an individual paying out of pocket, it's the steepest price in this category, and you should be honest with yourself about whether you need the preview pane and cloud connectors or just fast email search. There's no permanently free tier.

Alternatives to consider

The closest substitute is Copernic Desktop Search — same files-plus-Outlook concept, friendlier interface, cheaper subscription, weaker preview and no SharePoint connector. If your searches are about file contents rather than email, the free Agent Ransack does on-demand boolean and regex content search with a solid preview and costs nothing. And for raw filename lookups, Everything is instant and free — many X1 shops run both. Our best file search software roundup compares all of them in one table, and the Windows search hub covers what to try before spending anything.

Frequently asked questions

Final verdict

X1 Search scores 8/10 because it delivers exactly what it promises at a level nothing else quite matches: one keystroke-fast search surface over your files, your mailbox, and your cloud documents, with a preview pane good enough to replace opening applications. The deductions are practical, not philosophical — per-seat pricing that excludes most home users, a heavyweight index, an interface that leads with density, and a Windows-only footprint. If your business runs on Outlook and SharePoint, X1 is the best search money can currently buy. If it doesn't, you can get most of the way there for less.