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Quad9 vs Zscaler Internet Access comparison

Why PeerSpot?
 

Comparison Buyer's Guide

Executive SummaryUpdated on Jun 3, 2026

Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Categories and Ranking

Quad9
Ranking in Internet Security
6th
Average Rating
6.0
Reviews Sentiment
7.9
Number of Reviews
2
Ranking in other categories
Managed DNS (4th)
Zscaler Internet Access
Ranking in Internet Security
2nd
Average Rating
8.4
Reviews Sentiment
6.7
Number of Reviews
60
Ranking in other categories
Secure Web Gateways (SWG) (3rd)
 

Mindshare comparison

As of October 2026, in the Internet Security category, the mindshare of Quad9 is 4.4%, down from 5.5% compared to the previous year. The mindshare of Zscaler Internet Access is 27.9%, down from 32.2% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Internet Security Mindshare Distribution
ProductMindshare (%)
Zscaler Internet Access27.9%
Quad94.4%
Other67.7%
Internet Security
 

Featured Reviews

Louis Geoffroy - PeerSpot reviewer
President at IDEBUG
It's easy to use and set up, but I've faced performance problems
I have experience with Quad9 and most other filtering solutions. Quad9 was working well initially, but it started slowing, so I switched to OpenDNS. I recently checked Tom's Hardware, an IT review site, and read a review of seven DNS filters. Open DNS was ranked the fastest, and Quad9 was second. Google was on there too, but they said it didn't filter enough.
VikasTiwari - PeerSpot reviewer
Senior Network Engineer at Anthology
Cloud security has transformed remote access and now supports zero trust for all users
The best features Zscaler Internet Access offers are Secure Web Gateway, URL filtering, SSL inspections, and policy-based access control. I find myself relying on Secure Web Gateway, URL filtering, SSL inspection, and policy-based access control the most because these are the main and top-most features I use regularly. Zscaler Internet Access has all of these types of features for securing all internet access and web inspections, allowing me to control all traffic through these features. Zscaler Internet Access features include a Secure Web Gateway for URL filtering, file type control, and inline SSL inspections. The second feature is a cloud firewall with Layer 3 to Layer 7 filtering control and stateful inspections. No hardware inspection or hardware firewall is required. I can also perform segmentations by users, location, and application. There is a cloud CASB solution available as well. Additionally, there is an advanced threat protection feature with signature-based behavioral detections, inline IPS, and zero-day threat protections. The cloud sandboxing solution scans unknown files and provides machine learning-based verdicts to prevent zero-day malware delivery in my environment. There is also a DNS security feature that provides DNS tunneling detections, malicious domain controls, and faster threat containment at the DNS layer. The data protection feature includes inline DLP and CASB-style cloud app control, data sovereignty enforcement, and browser isolation, which executes risky sites in isolated cloud browsers and prevents endpoint compromises. Zscaler Internet Access has positively impacted my organization by reducing the dependency on on-premises hardware and improving security posture, enabling faster user onboarding, and providing better performance for remote users. It has resulted in a drop in security incidents related to web threats and improved visibility into user activity. An area for improvement includes fine-grained troubleshooting tools, better policy simulations, and optimizations around initial configuration complexity.

Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:
 

Pros

"Setting up Quad9 is straightforward if you know what you're doing, and it's easy to use overall."
"The most valuable feature of Quad9 is that it is a free solution."
"The most valuable feature is bandwidth control."
"My advice for people looking into implementing Zscaler Internet Access is that it's quite stable."
"We have seen a lot of traction in the market and a lot of users adopting this solution, and we're able to control or manage all the remote locations from one place."
"Zscaler offers a centralized DLP solution for web, endpoint, and email."
"The most valuable feature is the ability to drop packets."
"The solution's most valuable features are its reliability and availability, measured by the number of ports it offers."
"We have seen an ROI; this is a well published product, and you get value for your money."
"Zscaler Internet Access is very scalable, and requests for scalable solutions are met quickly."
 

Cons

"It used to work fine for all the devices, but it started to slow and become non-responsive. I would have to reload the page two or three times before all the pages loaded. With OpenDNS, I only need to load the page once."
"Quad9 could improve by having more free features, such as custom DNS filtering."
"The OS capabilities and WSL support could be improved."
"There are a few features that are not compatible with the Azure cloud."
"Zscaler Internet Access's troubleshooting is very limited, and their textbook logs need to be more informative."
"The license is per user, and there's a minimum license per user per year. It's costly if you compare it to the traditional solutions like Symantec or Bluecoat."
"It also needs better integration with other applications as well. There are some restrictions."
"We did hit a problem a while back where they didn't scale properly and we had some major issues."
"I believe, when you use Zscaler, you are not protected from all malware and malicious attacks, so you may need another tool just to cover these gaps."
"Sometimes it's not easy to use during large deployments of workstations. It's a bottleneck from a network point of view."
 

Pricing and Cost Advice

"The price of Quad9 is free."
"It is quite expensive. It does its job, but it is quite expensive for what we need."
"The pricing is an issue. It is expensive compared to other firewalls on the market."
"Because it's a cloud solution, we pay on a yearly basis. It is affordable and includes tech support and all features."
"​Be aware that you will need to invest some time and money to adapt your environment for Zscaler (traffic redirection, software deployment, authentication, etc).​"
"Zscaler is transparent about its pricing model."
"If we need any extra features, the price will increase."
"There are multiple bundles: enterprise, business, and transformation. Transformation includes all the features, but recently I've seen a few more line items that are additional costs. Overall, it's expensive."
"Our monthly fee is around R3000."
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915,325 professionals have used our research since 2012.
 

Top Industries

By visitors reading reviews
Comms Service Provider
27%
Computer Software Company
8%
Hospitality Company
6%
Financial Services Firm
5%
Financial Services Firm
11%
Manufacturing Company
10%
Computer Software Company
9%
Comms Service Provider
7%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
No data available
By reviewers
Company SizeCount
Small Business17
Midsize Enterprise9
Large Enterprise39
 

Questions from the Community

Which would you choose - Cloudflare DNS or Quad9?
Cloudflare DNS is a very fast, very reliable public DNS resolver. It is an enterprise-grade authoritative DNS service that offers great redundancy and advanced security with built-in unmetered and ...
Which is the better security solution - Cisco Umbrella or Zscaler?
Cisco Umbrella and Zscaler Internet Access are two broad-spectrum Internet security solutions that I have tried. Zscaler Internet Access is a good option for carrying out multiple security functi...
Which is better, Zscaler internet access or Netsckope CASB?
We researched Netskope but ultimately chose Zscaler. Netskope is a cloud access security broker that helps identify and manage cloud applications, protecting your sensitive data from exfiltration....
What is your experience regarding pricing and costs for Zscaler Internet Access?
We have not purchased Zscaler Internet Access through the AWS Marketplace; the licensing process was handled separately by our financial and management team.
 

Also Known As

No data available
ZIA
 

Overview

 

Sample Customers

CISCO, Netlab, proofpoint
Ulster-Greene ARC, BanRegio, HDFC, Ralcorp Holdings Inc., British American Tobacco, Med America Billing Services Inc., Lanco Group, Aquafil, Telefonica, Swisscom, Brigade Group
Find out what your peers are saying about Quad9 vs. Zscaler Internet Access and other solutions. Updated: September 2026.
915,325 professionals have used our research since 2012.