Brandwave

Superhuman vs Thunderbird:Which is more popular?

In September 2026, Thunderbird had more branded searches than Superhuman among email clients worldwide. Thunderbird had about 29,100 branded searches, while Superhuman had 27,000. Thunderbird made up 25.9% of all email client searches we track, and Superhuman accounted for 24%. When we asked ChatGPT and Google AI Overviews about email clients, Thunderbird appeared in four of the five answers and Superhuman in three. Thunderbird was mentioned before Superhuman in four out of five answers.

Among email clients worldwide in September 2026

Who do people search for more?

Thunderbird, about 8% more searches than Superhuman

Thunderbird 29.1K searchesSuperhuman 27K searches

Who does AI mention more?

Thunderbird, mentioned in 4 of 5 answers, Superhuman in 3

Thunderbird in 4 of 5Superhuman in 3 of 5

Who does AI recommend more?

Thunderbird, named ahead of Superhuman in 4 of 5 answers

Thunderbird first in 4Superhuman first in 1

Follow Superhuman vs Thunderbird and get free monthly updates on what changed

By continuing you'll get index updates and occasional product news from Brandwave. Unsubscribe any time. Privacy

Track your brand against a rival →

Top email clients in ChatGPT and Google AI Overviews

In three ChatGPT questions and two Google AI Overviews, Thunderbird was mentioned in four out of five: in all three ChatGPT answers and in one of the two Google AI Overviews. Superhuman was mentioned in three out of five: in two of the three ChatGPT answers and in one of the two Google AI Overviews. Thunderbird was listed before Superhuman in four out of five answers.

Most recommended by AI

Brands get a higher ranking if they are mentioned earlier in the answers.

  1. Spark1st
  2. Thunderbird2nd
  3. Proton Mail3rd
  4. Superhuman4th
  5. Airmail–
  6. Newton–

Mentioned by AI

Each dot is one answer, filled in when that answer mentions the brand.

  • Spark4 of 5Named in 2 of 3 ChatGPT answersNamed in 2 of 2 Google answers
  • Thunderbird4 of 5Named in 3 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Superhuman3 of 5Named in 2 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Proton Mail3 of 5Named in 2 of 3 ChatGPT answersNamed in 1 of 2 Google answers
  • Airmail0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers
  • Newton0 of 5Named in 0 of 3 ChatGPT answersNamed in 0 of 2 Google answers

See every answer about email clients

5 answers

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 Superhuman or Thunderbird more popular in search?

This chart shows how often people search Google for Superhuman and Thunderbird by name. Each line represents a brand's share of searches for all six email clients we track, month by month, from English-language searches worldwide.

Superhuman and Thunderbird among email clients worldwide, by month

Share of searches by month for Thunderbird, Superhuman. The figures are in the table below the chart.

View monthly share of searches table
MonthSparkThunderbirdSuperhumanAirmailNewtonProton Mail
Oct 202523.5%36.1%20.2%19.3%0.76%0.12%
Nov 202521.6%34.5%25.1%17.7%0.97%0.14%
Dec 202520.2%34%23.8%20.3%1.5%0.13%
Jan 202618.6%38.3%26.8%15.3%0.84%0.14%
Feb 202614.6%39%33.3%12%0.99%0.17%
Mar 202615.6%36.5%34.1%12.8%0.76%0.18%
Apr 202615.6%36.5%33.5%12.8%1.4%0.15%
May 202616.8%34.7%36.4%11.3%0.67%0.16%
Jun 202621.4%29.6%27.7%17.6%3.5%0.2%
Jul 202620.7%35%29.1%13.9%1.1%0.24%
Aug 202622%35.2%23.7%18.1%0.71%0.26%
Sep 202636%25.9%24%13.2%0.64%0.28%

How has the Superhuman and Thunderbird comparison changed over the last 12 months?

3 findings
  • The lead changed hands 2 times in the 12 months ending September 2026: Superhuman took it in May 2026, Thunderbird took it in June 2026.
  • Across the 12 months ending September 2026, Superhuman’s share of searches among email clients worldwide moved from 20.2% to 24%, and its estimated monthly branded searches moved from 23.4K to 27K.
  • Across the 12 months ending September 2026, Thunderbird’s share of searches among email clients worldwide moved from 36.1% to 25.9%, and its estimated monthly branded searches moved from 41.6K to 29.1K.

How did search popularity change for email clients worldwide in September 2026?

3 changes

  1. In September 2026, Spark overtook Thunderbird and Superhuman to become the leader among email clients worldwide, with 36% of the searches.

  2. In September 2026, Thunderbird lost share of searches among email clients worldwide, from 35.2% to 25.9%.

  3. Estimated monthly branded searches for Superhuman worldwide rose 15.6% over 12 measured months, from 23.4K to 27K in September 2026.

How are branded searches counted?

7 search terms

Brandwave collects information about searches that people make online using Superhuman’s and Thunderbird’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.

Superhuman

4 branded search terms

  • superhuman ai
  • superhuman ai email assistant
  • superhuman email
  • superhuman email client

Thunderbird

3 branded search terms

  • thunderbird client
  • thunderbird email
  • thunderbird email client

How the Brand Demand Index is measured

Other head-to-heads among email clients

Creator with pink hair and a pink jacket

Put your own brand in this comparison

Brandwave tracks your branded demand next to the rival you actually watch, with your campaigns, spend and outcomes on the same timeline.

Start free