Bitdefender vs Microsoft Defender:Which is more popular?
In September 2026, Microsoft Defender had more branded searches than Bitdefender among antivirus software worldwide. Microsoft Defender had about 181,000 branded searches, while Bitdefender had 90,500. Microsoft Defender made up 7.5% of all antivirus software searches we track, and Bitdefender accounted for 3.8%. When we asked ChatGPT and Google AI Overviews about antivirus software, both Bitdefender and Microsoft Defender appeared in all four answers. Bitdefender was mentioned before Microsoft Defender in every answer.
Who do people search for more?
Microsoft Defender, about 2 searches for every 1 for Bitdefender
Who does AI mention more?
Both are mentioned in every answer we collected.
Who does AI recommend more?
Bitdefender, named ahead of Microsoft Defender in every answer
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Top antivirus software in ChatGPT and Google AI Overviews
In three ChatGPT questions and one Google AI Overview, both Bitdefender and Microsoft Defender showed up in all four answers. Bitdefender was listed before Microsoft Defender in every answer.
Most recommended by AI
Brands get a higher ranking if they are mentioned earlier in the answers.
- Bitdefender1st
Norton2nd- Microsoft Defender3rd
Malwarebytes4th
McAfee5th
ESET6th
Kaspersky–
Mentioned by AI
Each dot is one answer, filled in when that answer mentions the brand.
- Norton4 of 4Named in 3 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- Microsoft Defender4 of 4Named in 3 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- Bitdefender4 of 4Named in 3 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- ESET2 of 4Named in 2 of 3 ChatGPT answersNamed in 0 of 1 Google answers
- Malwarebytes2 of 4Named in 1 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- McAfee1 of 4Named in 0 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- Kaspersky0 of 4Named in 0 of 3 ChatGPT answersNamed in 0 of 1 Google answers
See every answer about antivirus software
4 answers
Asked ChatGPT
“Which antivirus software should I use?”
Asked ChatGPT
“What are the best antivirus software options?”
Asked ChatGPT
“What's the best antivirus software for a home computer?”
Searched Google, AI Overview
“antivirus software”
Searched Google, AI Overview
“computer security software”
Google showed no AI Overview for this search.
Not named in any answer:
Brands are shown in the order each answer named them. The survey took place in the United States on October 20, 2026.
Is Bitdefender or Microsoft Defender more popular in search?
This chart shows how often people search Google for Bitdefender and Microsoft Defender by name. Each line represents a brand's share of searches for all seven antivirus software we track, month by month, from English-language searches worldwide.
Share of searches by month for Microsoft Defender, Bitdefender. The figures are in the table below the chart.
View monthly share of searches table
| Month | Norton | McAfee | Kaspersky | Microsoft Defender | Bitdefender | ESET | Malwarebytes |
|---|---|---|---|---|---|---|---|
| Oct 2025 | 37.2% | 27% | 23.2% | 8.4% | 3.1% | 0.93% | 0.12% |
| Nov 2025 | 35.5% | 28.3% | 24.9% | 7.4% | 2.7% | 1% | 0.11% |
| Dec 2025 | 35.3% | 28.4% | 25% | 7.5% | 2.8% | 1% | 0.11% |
| Jan 2026 | 35% | 31.4% | 22.7% | 7.4% | 2.5% | 0.91% | 0.1% |
| Feb 2026 | 36.3% | 30.4% | 21.9% | 8% | 2.4% | 0.88% | 0.12% |
| Mar 2026 | 35.9% | 30.8% | 21.6% | 7.9% | 2.9% | 0.87% | 0.11% |
| Apr 2026 | 34.3% | 28.3% | 24.3% | 8.8% | 3.3% | 0.98% | 0.13% |
| May 2026 | 33.8% | 28.9% | 24.9% | 9.1% | 2.2% | 1% | 0.13% |
| Jun 2026 | 36.5% | 29.8% | 22% | 8% | 2.4% | 1.1% | 0.12% |
| Jul 2026 | 35.6% | 28.6% | 21.5% | 7.8% | 5.2% | 1.1% | 0.11% |
| Aug 2026 | 36.1% | 27.3% | 24.6% | 8.1% | 2.7% | 1.2% | 0.11% |
| Sep 2026 | 39.2% | 25.4% | 22.9% | 7.5% | 3.8% | 1.1% | 0.1% |
How has the Bitdefender and Microsoft Defender comparison changed over the last 12 months?
3 findings
- Microsoft Defender was ahead of Bitdefender in every measured month of the 12 months ending September 2026.
- Across the 12 months ending September 2026, Bitdefender’s share of searches among antivirus software worldwide moved from 3.1% to 3.8%, and its estimated monthly branded searches held steady at 90.5K.
- Across the 12 months ending September 2026, Microsoft Defender’s share of searches among antivirus software worldwide moved from 8.4% to 7.5%, and its estimated monthly branded searches moved from 245K to 181K.
How did search popularity change for antivirus software worldwide in September 2026?
2 changes
In September 2026, Bitdefender gained share of searches among antivirus software worldwide, from 2.7% to 3.8%.
In September 2026, Microsoft Defender lost share of searches among antivirus software worldwide, from 8.1% to 7.5%.
How are branded searches counted?
3 search terms
Brandwave collects information about searches that people make online using Bitdefender’s and Microsoft Defender’s names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.
Bitdefender
1 branded search term
- bitdefender antivirus
Microsoft Defender
2 branded search terms
- microsoft defender
- windows defender
Other head-to-heads among antivirus software
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