X1 Search vs Copernic Desktop Search: Which One for Outlook? (2026)

X1 Search and Copernic Desktop Search are the two best-known Windows desktop search tools that also search Outlook, and they often end up on the same shortlist. They are not built for the same buyer. Copernic is a low-cost personal indexer for files, cloud drives and email, listed from €25.99 a year. X1 Search costs $79 a year and reaches across Microsoft 365, Slack and file shares, with the filters that investigation work needs. Below: what each costs, how each reaches your Outlook mail, what else it searches, how its AI works, and when neither is the right tool.

Disclosure: Inbox Search is our product, and it appears near the end of this comparison. X1 Search and Copernic details come from x1.com and copernic.com, checked on November 3, 2026. Prices and features change, so treat the vendors' own pages as authoritative over this one.

The short answer

• Choose Copernic if you want one search box over your own PC's documents, PDFs, cloud drives and a local Outlook or PST files, at the lowest price, on Windows.
• Choose X1 Search if you search across Microsoft 365 as a whole (Teams, SharePoint, OneDrive, the Online Archive) or Slack, need deep metadata filters, or do investigation or compliance work.
• Choose neither if you use a Mac or Outlook on the web, since both are Windows-only, or if email is the only thing you search and keyword matching keeps missing it.

What do X1 Search and Copernic cost in 2026?

Both sell yearly licences with a free trial. As of November 3, 2026:

Copernic's plans come on one-, two- or three-year terms with a 30-day trial. Its pricing page labels the figures illustrative, which is why we say "listed at". On the Basic plan, an Outlook 365 account without a local Outlook needs a separate extension listed at US$30 a year. X1 offers a 14-day trial, prices volume and enterprise licences through its sales team, and was showing a 20% discount on its purchase page when we checked.

For one person, Copernic costs less than X1 on Basic and Advanced, and about the same on Elite, depending on the exchange rate. If your mail is in Microsoft 365 and you do not run classic Outlook, the fair comparison is Copernic Advanced at €39.99 against X1 at $79, not Basic.

How does each one reach your Outlook email?

For anyone buying because Outlook cannot find an email, this decides more than the price, and the two tools answer it differently.

Copernic: a local Outlook, or a higher plan

Copernic's feature table says its Outlook and PST search requires "a local Microsoft Outlook installation or local .PST file(s)". With classic Outlook on Windows, that works on every plan. Indexing a Microsoft 365 mailbox directly, without a local Outlook, is a separate feature: included from the Advanced plan, or sold as the extension on Basic. The new Outlook for Windows and Outlook on the web keep your mail in Microsoft 365 rather than in a local profile, so that is the route their users need.

X1 Search: Microsoft 365 and other mail accounts

X1 lists its Microsoft 365 sources by name: Exchange, Outlook, the Microsoft Online Archive, and contacts and calendar, alongside Teams, SharePoint and OneDrive. It also searches Gmail through an API connector, Yahoo, AOL and other IMAP accounts, and PST files and archived email. Its page does not name the new Outlook for Windows, and its FAQ lists Outlook 2007 to 2016, so if you use the new Outlook, check it during the trial.

The Online Archive deserves a note. Many work mailboxes move older mail there automatically, and it is where most search tools stop. X1 lists it; Copernic's pricing page does not mention it.

What else do they search?

Neither is an email tool first. Both index far more than your mailbox, and this is where they differ most.

• Copernic indexes local files and Office documents, PDFs, and cloud drives such as Dropbox, Google Drive and OneDrive, across what it calls "hundreds of file extensions". Elite adds Teams, SharePoint, Gmail and OCR for scanned documents. A server edition indexes shared storage centrally for a business.
• X1 Search indexes local files and file shares, Microsoft 365 (Teams, SharePoint, OneDrive), Slack, Google Drive, Box and Dropbox. It offers search as you type, hit highlighting, previews of files in their native format and more than 50 metadata filters.

If your working day is mostly your own documents and a classic Outlook profile, Copernic covers it for less. If it runs through Teams, SharePoint and Slack as much as through email, X1 is the one that reaches all of it.

AI features: your own hardware or a cloud model

Both tools now add AI to a keyword index, in opposite ways.

• X1 Search uses AI to classify and tag emails, documents, chats and attachments, which X1 says improves relevance and helps identify sensitive information. It says its models are applied "within your environment", and recommends 16 GB of RAM and a dedicated Nvidia or AMD graphics card for them. They also run on the processor alone, but X1 warns that performance may then be much lower.
• Copernic sells an AI extension on Advanced and Elite that adds semantic search, a query assistant, summaries and translation. It is powered by Google Gemini or OpenAI, so it relies on a cloud model rather than running on your PC, and when we checked in October 2026 it used your own Gemini or OpenAI account. Copernic's ordinary indexing stays on your PC.

On Copernic Basic and on X1, the search you run every day is keyword matching: fast and exact when you remember the words, and empty when the sender chose different ones.

Platforms and hardware

• Both are Windows-only. X1 lists Windows 10 and 11 and says Mac and Windows on Snapdragon (ARM) processors are not supported, with no Mac release imminent. Copernic offers x64 and x86 installers and an MSI package, and lists no Mac or web version.
• X1 asks for more of the machine. Its page gives 8 GB of RAM and 20 GB of free storage as the base, before the AI recommendation above.

X1 Search vs Copernic at a glance

When neither is the right tool

Both are desktop indexers for Windows. Three situations call for something else:

• You use a Mac or Outlook on the web. Neither runs there.
• Email is the only thing you search. Keeping an index of your whole PC, or of your whole Microsoft 365 account, to find one message is a lot of machinery for an inbox problem.
• You cannot find emails because you do not remember the wording. A keyword index matches the words you type. If the sender wrote "Your stay is confirmed" and you search for "hotel reservation", it has nothing to match.

For those cases, Inbox Search is an Outlook add-in that finds emails by meaning entirely on your device. It runs inside Outlook rather than beside it, so it works the same in the new Outlook and classic Outlook on Windows, in Outlook for Mac and in Outlook on the web, with no local profile, PST file or extension to arrange. It combines semantic search with keyword matching, so exact terms such as an invoice number still come first, and its AI model was trained on more than 50 languages.

It is also narrower than either tool above. It searches email in your primary mailbox only: no files, no shared mailboxes and no Online Archive. Keyword search and indexing are free and unlimited, with 5 AI finds a day; Pro removes the limit for €7.99 a month or €79 a year, VAT included, with a 7-day free trial (see pricing).

Which one should you pick?

• Your files and a classic Outlook profile, on one Windows PC, on a budget: Copernic Basic.
• Your mail is in Microsoft 365 and you want your files too, for less than X1: Copernic Advanced.
• Teams, SharePoint, Slack and the Online Archive in one search, or investigation work: X1 Search.
• Only email, on any platform, or searches that keep failing on wording: Inbox Search.

All three have free trials and none of them changes your mailbox, so the fairest test is to install two side by side and search for five emails you struggled to find recently. For the wider field, see our comparison of the best Outlook search tools, or the X1 Search alternatives and Copernic alternatives on their own.

Frequently asked questions

X1 Search vs Copernic: which is better? It depends on what you search. Copernic is the cheaper choice for one person's files, cloud drives and a local Outlook or PST files, listed from 25.99 euros a year. X1 Search, at $79 a year, reaches further: Microsoft 365 including Teams, SharePoint and the Online Archive, Slack, and other mail accounts, with more than 50 metadata filters. Both run on Windows only, and everyday search in both is keyword matching.

Do X1 Search and Copernic work with the new Outlook? Copernic needs a local Outlook installation or PST files on its Basic plan; indexing a Microsoft 365 mailbox without local Outlook needs the Advanced or Elite plan, or an extension listed at US$30 a year. X1 Search connects to Microsoft 365 and Exchange, but its page does not name the new Outlook, so test it during the 14-day trial. Inbox Search runs inside the new Outlook as an add-in.

Do X1 Search and Copernic work on a Mac? No. As of November 2026 both are Windows-only, and X1 says no Mac release is imminent. For email on a Mac, an Outlook add-in such as Inbox Search runs in Outlook for Mac and Outlook on the web.

Is X1 Search or Copernic cheaper? Copernic, on its Basic and Advanced plans: listed at 25.99 and 39.99 euros a year, against $79 for X1 Search. Copernic Elite, listed at 84.99 euros, costs about the same as X1. Copernic labels its prices illustrative and X1 runs promotions, so check both pages before buying.