Npcap OEM Edition—Redistribution License

Npcap is the Nmap Project's packet sniffing (and sending) library for Windows. While Npcap has many end users who simply use the free/demo version, we fund the Npcap project by selling the enhanced Npcap OEM Edition. This special version includes enterprise features such as the silent installer and commercial support as well as special license rights allowing customers to redistribute Npcap with their products. The primary differences between OEM Npcap and the free/demo Npcap releases are:

This page describes the Npcap OEM redistribution license for companies that wish to redistribute Npcap OEM outside of their organization (e.g., within their products). Organizations that only want to use Npcap OEM internally (within your organization, including your employees, contractors, etc.) without any redistribution outside the org qualify for the Npcap OEM internal-use license instead. The redistribution license already allows unlimited internal use for development and testing and usage of your product. You only need to buy both licenses if you want to redistribute Npcap in your product(s) and also use Npcap internally in a manner unrelated to those products.

Npcap OEM releases are always made in conjunction with Npcap free/demo releases, and the version numbers are the same. Since Npcap OEM is almost identical to the free/demo Npcap, more product details are available from the Npcap public pages and we won't try to reproduce all of that here.

Redistribution License Prices & Terms

To keep things simple our standard Npcap license involves no per-seat royalties--just a reasonable one-time license buy-out fee and an optional annual maintenance fee which includes all new Npcap releases as well as commercial support. That maintenance fee never increases for as long as you keep renewing. We also offer a quarterly term license which includes redistribution rights and maintenance for a fee paid every three months for as long as you are selling new products containing Npcap OEM. The quarterly term license fee never increases either.

Prices are in U.S. Dollars (USD) based on the size of company buying the license, broken into four tiers. This is because larger companies are usually able to derive more value from Npcap OEM by leveraging it at a greater scale. Larger companies generally cost us more to support as well. Prices are based on the whole company size, not just an individual division or development team. The prices are locked in after purchase, so they don't increase as companies grow later.

All perpetual licenses include a six-month trial period during which you can cancel for any reason and receive a full refund of all money paid. The term license is only a 3-month commitment and can also be terminated with a full refund during the first 30 days of the initial quarter. We also provide a free/demo version of Npcap that you can fully test internally before purchase.

The rights Npcap OEM redistribution license customers enjoy are spelled out in the sample license certificate. This includes support, indemnification, warranty, updates, etc. A filled-out version containing software download credentials is provided for each purchase.

Purchase Process (Redistribution License)

While we hope to set up an online store for immediate purchase, we currently have a more manual Npcap purchase process. To buy an Nmap OEM Internal-use license, you or your preferred reseller should send a message to with the following information:

  1. Your company name if it isn't obvious from your email address or email signature. For resellers we need the end user company name.
  2. Which license you want. This depends on your current company size as described here and would be either the Npcap OEM Enterprise Redistribution License, Npcap OEM Mid-Sized Company Redistribution License, or the Npcap OEM Small/Startup Company Redistribution License.
  3. If this is the Enterprise Redistribution License, the license covers a named product line or category (which can be fairly broad). Please include the product line name or category that you are interested in shipping with Npcap OEM. This is not needed for the smaller company licenses since those companies usually have fewer products.
  4. Do you want the perpetual license or the quarterly term license? The term license is paid every 3 months until you cease redistributing Npcap OEM and notify us of license termination. Companies choosing the quarterly license must either set up auto-payments or pay the automated invoices that we email to them. We can handle initial vendor onboarding for the term license, but not individual (per payment) purchase orders, enterprise payment portals, etc.
  5. If it's a perpetual license, do you want 5 years of updates and support (with the 20% prepayment discount), 1 year of maintenance (with possible renewals later), or no maintenance at all? We strongly recommend buying maintenance for the redistribution license to avoid installing old/obsolete versions on end user systems. Npcap OEM is under very active development, with dozens of feature enhancements, bug fixes, and performance improvements made every year. Maintenance also includes support, so you're covered if any end users experience problems or ask you questions about Npcap. The annual maintenance price never increases for as long as you keep renewing. Please note that the term license always includes maintenance as part of the quarterly fee.
  6. Would you like an invoice that you can pay directly (using international wire transfer, U.S. direct deposit, check, etc.) or a quote which you can use internally within your company to generate a purchase order for us to invoice against? Invoices under US$10,000 may also be paid by credit card, and we can also add credit card or PayPal payment links to larger invoices upon request.

Once we receive your request, we will send a formal quote with instructions for payment by wire transfer, ACH direct deposit, or check. You can pay that directly or begin your company's procurement process for vendor onboarding, purchase order request, etc.

As soon as payment or a purchase order is received, we will activate your license and send you the following:

Downloading and Installing Npcap OEM

Current licensees can find the Npcap OEM installer itself in this distribution directory. If you don't remember your company's username and password, please contact Be sure to download the latest version unless you specifically require an older one. Note that updating Npcap to later versions requires a maintenance (support and upgrades) subscription. If you aren't sure whether you have an active maintenance subscription, email and we will check for you.

Npcap OEM utilizes the same SDK as normal Npcap, and that is available from the Npcap public pages.

Current Nmap Security Scanner licensees who want access to Npcap for use with Nmap should see this FAQ question.

Support and Documentation for Npcap OEM

Npcap OEM shares its documentation with the public/demo version of Npcap. All of the documentation (and even the source code) is available by hyperlink from the Npcap public pages.

Licensees with an active maintenance (support and updates) subscription have special access to report bugs or ask Npcap technical support questions. If you are a licensee and don't have the support contact information, please email and we will send it to you.

FAQ - Frequently Asked Npcap OEM Questions

  1. Is maintenance (support and updates) optional?

    For our normal (perpetual) license, maintenance is optional but highly recommended because it extends the perpetual license to include all new versions released during the maintenance period. And Npcap is under very active development with dozens of feature enhancements, bug fixes, and performance improvements made every year. Maintenance also includes commercial support whenever you need it. And the price never increases as long as you don't let it lapse for more than 120 days.

    For our term license, maintenance (including all updates and commercial support) is included along with redistribution rights in the quarterly fee (which never increases).

  2. Is the first year of maintenance included in the perpetual license fee?

    No. While we strongly recommend maintenance for the reasons given in the last question, some of our customs choose to decline even the first year of maintenance. Others choose the 5-year prepaid options for a 20% discount. Quoting the license and maintenance prices separately allows customers to make their own selections.

  3. Do you sell through resellers?

    Yes, we are happy to sell through your preferred reseller. We regularly work with SoftwareONE, SHI, and dozens of others. Just ask your reseller to contact on your behalf with the information requested in Purchase Process.

  4. If we already have (or plan to buy) a commercial Nmap Security Scanner OEM redistribution license, do we also need to buy an Npcap license for use with Nmap?

    No. Our Nmap OEM product includes custom Windows builds (both an installer and a zip file of binaries) which already include Npcap OEM. This license includes full rights to redistribute Npcap OEM or use it for testing/development if Npcap is only being used with Nmap. Your Nmap OEM credentials can also be used to download the latest version of Npcap OEM in case you want to use (or test) a newer version than ships with Nmap. Links and details are available from the Nmap OEM page.

    Please note that an Nmap OEM commercial license does not confer distribution rights to use Npcap OEM with non-Nmap software. For that you would need the Npcap OEM redistribution license described by this page, but at least you would receive an existing-customer discount. Please email for details.

  5. What are the standard license terms and what if they don't work for us?

    Our standard license terms are available in a license certificate we send customers (filled out of course). We provide indemnification and allow virtually unlimited use of the Npcap OEM technology in your products. We also provide source code in case you desire to make any changes or just better understand Npcap's workings. The agreement includes a 6-month trial period during which you can terminate for any reason and receive a full refund of all money paid.

    While many customers prefer our newer certificate approach because it's quicker and removes the need to review and sign a contract, others prefer a contract signed by both parties. Our standard Npcap OEM perpetual redistribution license contract template is available as a PDF, or editable MS Word version, and the quarterly term contract template is also available in PDF, and Word formats.

    If you only need a very small change, we may be able to modify the license certificate version for you. If your legal department wants to make many changes, the contract version is probably better. Please note that extensively marking up the contract will require significant legal review time on our side, and changes which substantially increase our obligations will increase the license fee too. Major markups are only allowed for the Mid-Sized or Enterprise license sizes. Customers interested in the Small/Startup license will have to limit themselves to a very small number of very minor changes (if any), or upgrade to the more expensive license.

  6. What if Npcap OEM doesn't work out for us? Do you offer a trial license or a way to return it for a refund?

    Our redistribution license certificate (Section 5.4) includes a 6-month period from the software delivery date during which you can cease redistributing Npcap OEM and request a full refund for any reason. Refunds include any maintenance fees already paid as well as any license fees, and they are provided within 30 days. So you don't lose a penny if you aren't happy with Npcap OEM or if the project you hoped to use it for doesn't pan out. Any licenses you have already granted to end users remain valid. While most customers choose our redistribution license certificate, the contract version of our licenses also includes this 6-month refund provision (see license terms).

    We also offer the free/demo version of Npcap for download and testing. While this lacks some convenience features of Npcap OEM (such as the silent installer), and doesn't allow redistribution, the actual driver functionality is virtually identical. So you can perform initial pre-purchase functionality testing with this.

  7. Are there any limits or extra fees based on how many copies of Npcap OEM we redistribute or install?

    No. You can distribute and install as many copies of Npcap OEM as you wish as part of products covered by your license for no additional fees.

  8. If our company size increases to a higher tier, or if Npcap prices go up in general, will we have to pay more?

    No. The optional annual maintenance fee for perpetual licenses and the quarterly license fee for term licenses are set based on your company size and the current prices at the time you buy the license. They don't increase for as long as you choose to renew.

  9. My company is huge, but only 5 people are on the development team for the product which needs Npcap. Can we qualify for the startup rate?

    No. The license tiers are based on the whole company (or parent company) size. This is because large companies often have the financial and market power to leverage far more value out of Npcap than a tiny company can, even when the development team sizes for an individual product are similar.

  10. Where is the Npcap OEM SDK?

    There is no need for a separate Npcap OEM SDK because all software compiled with the normal Npcap SDK is 100% compatible with both the free/demo Npcap and Npcap OEM. Download the Npcap SDK here.

  11. What is Npcap's US Export Control Classification Number (ECCN)?

    Npcap is published software which does not contain encryption (it operates at a lower level than encryption) and so it is classified as EAR99. It generally doesn't require any export license from the U.S. except for provisions that apply to most goods such as shipping to embargoed countries like North Korea.

  12. Can you provide a "private branded" Npcap with customized driver and DLL names so that it can only be used by our software and can be installed alongside any other copies of Npcap OEM or demo Npcap used by other software?

    While this idea is appealing, it is not practical for Windows device drivers like Npcap for several reasons:

    • Having multiple copies of Npcap loaded into the Windows kernel would degrade performance as each copy had to inspect all network traffic independently.
    • Microsoft Windows limits resources such as filter driver slots and memory usage, and those limits could be reached if each application using Npcap also started its own Npcap driver instance. Especially if the system also used other network filter drivers such as VPNs and personal firewalls.
    • Npcap driver releases involve a significant amount of work to sign them correctly (which must be done manually with a physical USB key present to unlock the EV certificate) and then submit them to Microsoft for their own testing and attestation signing.

    The good news is that we work very hard to make Npcap sharable between applications. An Npcap OEM installation will work with applications designed for both the free/demo Npcap or the OEM one, and vice versa. We also work hard to maintain forward and backward compatibility with different versions of Npcap. In the same way your application will share a system's other device drivers (video drivers, ethernet drivers, storage drivers), it should have no trouble sharing the Npcap OEM driver.

    The Npcap installer also allows you to specify which Npcap version(s) or feature(s) you want to require. You could even run the Npcap installer with these options each time it starts up. If an installed Npcap already meets your version and feature requirements, it will exit immediately. Otherwise Npcap will silently install to meet your requirements.