Low-Hanging Fruit in Podcasting (or why you should start an astronomy podcast)

Podcasts are the 21st century's radio, covering every subject under the sun and giving listeners a way to be informed, amused or outraged.

Being the podcast geeks that we are at Rephonic, we wanted to deep dive to find out where the opportunities are for new shows. We used the data that powers our podcast database to discover how various languages and categories are represented in the industry.


  • There is massive over-representation of certain languages including English, Indonesian and Swedish
  • Japanese and Russian podcasts are severely under-represented
  • Some categories are very oversubscribed in particular languages (e.g. Christianity)
  • Listeners are not so happy with certain categories like Astronomy (as measured by average ratings)

We've barely scratched the surface when it comes to serving the six billion or so non-English speakers around the globe.

More than 50% of the 2.7 million podcasts we track are published in English. Spanish comes in a distant second place at 11.7%.

Here's a pie chart showing podcast languages as a percentage of all shows:

Pie chart showing podcast languages as a percentage of all shows

See the footnotes for our methodology. We used podcast title, description and per-episode notes to detect the language [1].

📈 Podcasts published in English and Indonesian are significantly over-represented

English and Indonesian language podcasts are by far the most over-represented in our database, while Japanese and Russian are severely under-represented considering that they each have a large base of native speakers.

If you're launching a new podcast in English or Indonesian you should be extra careful about the category and niche you decide to target. It's going to be harder to stand out.

We looked at how many native speakers there are globally for each language compared to the number of podcasts published in that language. To make countries easier to compare we calculated a podcast language representation index.

Countries in green are over-represented, yellow adequately represented, and red means under-represented. [2]

Chart showing podcast language representation
Comparing podcast languages to number of speakers for that language globally.

Podcast titles, descriptions and episode notes were used to detect the language [1]. These were compared with the percentage of total native speakers globally to figure out how well represented the languages are in podcasting. [3]

Looking at the categories across all podcasts globally, Society & Culture is the most popular one, closely followed by Self-Improvement and then Christianity.

In general, podcasts are distributed pretty well across categories and no particular category dominates.

Please note that we only looked at the categories supported by Apple Podcasts. [4]

Pie chart showing popular podcast categories
Podcast primary category as a percentage of all shows globally.

🏏 Some languages over-represent certain categories (e.g. Cricket podcasts in English)

We calculated the most popular categories for each of the top ten languages (by number of native speakers) to see which categories are most over-represented relative to other languages and which categories are most crowded. [5]

In other words, the most over-represented category column shows categories that have an outsized representation in that language if you compare it to how many shows appear in that category for other languages.

Table showing the most over-represented and most crowded podcast categories for languages
Visualizing the most over-represented and most crowded podcast categories by language relative to the global average.

Taking Portuguese podcasts as an example:

There are close to 200,000 podcasts published in Portuguese and 407 of these are in the Chemistry category (0.2%). This may seem low, but the proportion of Chemistry podcasts globally is 0.05%. At 4X the global average, this category beats all of the others.

The analysis we conducted for the most crowded categories not only takes into account how well represented they are, but also the number of podcasts in that category. [6]

🙏 Christianity is the most crowded category across all English language podcasts

We hate to be the bearer of bad news, but a brand new Christianity podcast in English is going to be very difficult to get to the top of the charts given how competitive that category is.

It’s 1.3x over-represented, which you might think is not that much, but you’re up against over 100,000 shows to make the top spot.

Graph showing the popularity of Christianity podcasts in English

🔬 Chemistry and Islam are the most overlooked categories in English

Time for some low-hanging fruit. We looked at the five most overlooked categories across all English language shows. If you're starting a new podcast, this could be a good place to look. [7]

Graph showing the most overlooked podcast categories in English
Most under-represented podcast categories in English relative to global figures.

With the Islam category making up 0.45% of all podcasts globally and under 0.2% of all English language podcasts, it matches Chemistry to be one of the two most under-represented categories.

Either could be a great opportunity for a new podcast, but there are far fewer existing podcasts to outperform in the Chemistry category to gain the loyalty of listeners.

🏐 Volleyball is the least populated English language category

Which English language categories have the fewest shows, period? We ran the numbers and found some interesting results. [7]

If you want to compete in a category with the fewest number of podcasts, then Volleyball or Swimming are the ones to go for, with only 132 and 172 shows respectively.

Graph showing English language podcast categories with the fewest podcasts
Categories with the least number of shows in English.

🔭 Astronomy is the most unpopular category (as measured by listener ratings)

Another way to gauge where the opportunities are in podcasting is to look at the average ratings. We took a closer look at the top ten most unpopular categories in English as voted by listeners. [8]

Again we used green to show the over-represented categories for podcasts in English, yellow for adequately represented and red for underrepresented. [3]

The average rating across all podcasts in English is 4.7, so the Astronomy category is the only one that comes in below this.

Table showing the average rating of different podcast categories in English
Visualizing representation, average rating and number of podcasts in the ten most unpopular categories (English language podcasts only)


So, what are the best untapped opportunities for new podcasts? It’s hard to say. There are so many factors that affect the likelihood of a show being successful.

It’s useful to see the bigger picture when planning the launch of a new podcast and to look at things like the popularity of different categories and their ratings, but here’s our main piece of advice:

No matter which language or category you plan on launching a new podcast in, finding a niche that you can become an expert in is key to attracting and retaining an audience. Maybe you should start that new Christianity podcast in English, but find an angle that nobody else has covered before!

Rephonic is on hand to make that task much less daunting. We provide data for over two million podcasts so you can research the competition, get content ideas and, when you’re ready, find cross-promotional opportunities.

To learn more about Rephonic, check out this link and get started with a 7-day free trial.


[1] We used the podcast title, description and episode show notes to detect podcast language. It’s not always fully accurate and there are instances where we were not able to detect a language.

Also our podcast index is primarily based on the Apple Podcasts directory and this is likely to skew the results somewhat.

[2] This chart only shows languages where we had data for both podcast language and global native speakers, with the exception of Punjabi, Urdu, Gujarati, Kannada and Marathi because their podcast representation was too low to visualize.

We detected Chinese (Traditional) and Chinese (Simplified) as separate podcast languages and for the purpose of this analysis, we combined them to become Chinese (all). We used the table Languages with at least 10 million first-language speakers from this Wikipedia source as our measure of global native speakers. We combined all the languages that contain ‘Chinese’ to compare against the podcast language Chinese (all). We combined all the languages that contain ‘Arabic’ to compare against the podcast language Arabic. Iranian Persian is used for Persian.

[3] We used an index comparing podcast language and global native speakers to determine the representation of languages. Languages with an index = < 0.75 are underrepresented, > 0.75 < 1.25 are adequately represented and = > 1.25 are overrepresented.

[4] We used the primary category for podcasts as reported by Apple's podcast lookup API. This can be either a top-level category, e.g. 'Sports', or a sub-level category, e.g. 'Sports - Volleyball', which we reported simply as 'Volleyball'.

[5] We showed 10 languages from this complete table. Categories shaded in grey have fewer than 50 podcasts.

Most over-represented categoryMost crowded category
AfrikaansRugbySelf Improvement
BengaliHinduismPerforming Arts
Chinese (China)BuddhismPersonal Journals
Chinese (Taiwan)BuddhismLeisure
DanishVolleyballSociety & Culture
GermanSoccerSociety & Culture
GreekBasketballPersonal Journals
HindiHinduismPerforming Arts
HungarianBuddhismSociety & Culture
KoreanBuddhismPersonal Journals
MacedonianLanguage LearningLanguage Learning
MarathiHinduismPerforming Arts
NorwegianHome & GardenComedy
PunjabiHinduismLanguage Learning
RussianJudaismSociety & Culture

[6] We only included categories that have more than 5% of the total number of podcasts for that language.

[7] We excluded the iTunes U, Global Health and Social Welfare categories from these analyses as, globally, they only have 21, 1 and 2 podcasts respectively.

[8] We used Apple Podcasts reviews as a proxy for average ratings.

Becca Butcher

Becca Butcher

Marketing at Rephonic

Find, pitch and get featured on podcasts

Rephonic gives you listener numbers, contacts, demographics and more across 2.5m+ podcasts.

Becca Butcher

Becca Butcher

Marketing at Rephonic

Find, pitch and get
featured on podcasts

Rephonic gives you listener numbers, contacts, demographics and more across 2.5m+ podcasts.