At the end of 2025, the Haskell Foundation re-started the Haskell Yearly Survey. I’d like to thank Taylor Fausak for being supportive of our effort in conducting these surveys. The last survey was conducted in 2022 and the post discussing those results is here: https://taylor.fausak.me/2022/11/18/haskell-survey-results/
The full results are available here: State of Haskell 2025 Raw Results - Google Drive. If you’d like a CSV to play around with, that has been made available as well: 2025 Survey CSV.
I’m going to use this post as a way to discuss a subset of the results that I feel are interesting to the HF and likely to the wider community.
Do you use Haskell?
Let’s start from the top, who is taking the survey?
| Q1. Do you use Haskell | ||
|---|---|---|
| Answer Choices | Responses | |
| Yes | 72.26% | 1021 |
| No, but I used to | 16.28% | 230 |
| No, I never have | 11.46% | 162 |
| Answered | 1413 | |
| Skipped | 4 |
This is actually an increase in the number of people taking the survey since 2022 (~1,000), which was not our initial expectation! There is also an increase in the number of non-Haskellers taking the survey.
Of particular interest to me is when folks ‘drop off’ on using Haskell. This is hard to measure, because if they’re not using Haskell anymore they’re very unlikely to take the survey. That said we did get almost 200 responses to the following:
How long before stopping?
| Q2. If you stopped using Haskell, how long did you use it before you stopped? | ||
|---|---|---|
| Answer Choices | Responses | |
| Less than 1 day | 14.72% | 29 |
| 1 day to 1 week | 10.66% | 21 |
| 1 week to 1 month | 15.23% | 30 |
| 1 month to 1 year | 17.26% | 34 |
| More than 1 year | 42.13% | 83 |
| Answered | 197 | |
| Skipped | 1220 |
As might be expected, most fall off within a year. There’s a hump at “less than 1 day”, which can mean that we still have on-ramp issues. The rest fits what you would expect with most intellectual endeavors; as time goes on, more people drop off.
How have you used it?
| Q3. How many years have you been using Haskell? | ||
|---|---|---|
| Answer Choices | Responses | |
| Less than 1 | 11.12% | 95 |
| 1 to 2 | 8.78% | 75 |
| 2 to 3 | 8.67% | 74 |
| 3 to 4 | 6.32% | 54 |
| 4 to 5 | 8.43% | 72 |
| 5 to 6 | 5.85% | 50 |
| 6 to 7 | 5.27% | 45 |
| 7 to 8 | 6.67% | 57 |
| 8 to 9 | 3.98% | 34 |
| 9 to 10 | 7.26% | 62 |
| 10 to 11 | 5.04% | 43 |
| 11 to 12 | 2.93% | 25 |
| 12 to 13 | 1.87% | 16 |
| 13 to 14 | 2.34% | 20 |
| 14 to 15 | 1.52% | 13 |
| More than 15 | 13.93% | 119 |
| Answered | 854 | |
| Skipped | 563 |
This was very surprising to me! Pretty much half (49.17%) of those surveyed have been using Haskell for fewer than 6 years (i.e. since COVID), this is not the usual narrative that we tell ourselves in the community. We should try to figure out whether this is a quirk of the the sample population, as this implies that we still have a healthy population of ‘newer’ Haskellers picking up the language.
Haskell for work
| Q7. Do you use Haskell at work? | ||
|---|---|---|
| Answer Choices | Responses | |
| Yes, most of the time | 30.89% | 304 |
| Yes, some of the time | 18.29% | 180 |
| No, but my company does | 0.71% | 7 |
| No, but I’d like to | 42.68% | 420 |
| No, and I don’t want to | 7.42% | 73 |
| Answered | 984 | |
| Skipped | 433 |
This pretty much aligns with my expectations, but is still worth calling out. There is a healthy group of Industrial Haskell users (49.18% at least some of the time). However, there is a significant portion of people who want to be able to use Haskell at work, but currently do not. We have to help folks like this sell Haskell to their companies.
Project Size
| Q13. What is the total size of all the Haskell projects you contribute to? | ||
|---|---|---|
| Answer Choices | Responses | |
| Less than 1,000 lines of code | 24.71% | 216 |
| Between 1,000 and 9,999 lines of code | 26.54% | 232 |
| Between 10,000 and 99,999 lines of code | 25.17% | 220 |
| More than 100,000 lines of code | 23.57% | 206 |
| Answered | 874 | |
| Skipped | 543 |
Taylor measured this a little differently on this question, so direct comparison is difficult. What we can say is that the distribution is much more uniform than in 2022. This is likely from:
- more newer (smaller) projects
- some of the medium-large projects continuing to grow and becoming large-large
Haskell Dev Environment
| Q16. Which Haskell compilers do you use? | ||
|---|---|---|
| Answer Choices | Responses | |
| GHC | 99.40% | 991 |
| GHCJS | 3.91% | 39 |
| Clash | 1.91% | 19 |
| Hugs | 0.60% | 6 |
| Mu | 1.00% | 10 |
| MicroHS | 3.61% | 36 |
| Other (please specify) | 0.70% | 7 |
| Answered | 997 | |
| Skipped | 420 |
MicroHS is the new entry on this list and it has a fairly healthy user group already. I’d also be interested to know what folks are using Hugs for (though, that’s a personal curiousity of mine).
| Q17. Which installation methods do you use for your Haskell compiler? | ||
|---|---|---|
| Answer Choices | Responses | |
| ghcup | 63.45% | 632 |
| Nix | 41.57% | 414 |
| Stack | 20.88% | 208 |
| Operating system package | 11.75% | 117 |
| Official binaries | 3.71% | 37 |
| Source | 3.41% | 34 |
| Haskell Platform | 0.60% | 6 |
| Homebrew | 3.21% | 32 |
| Chocolatey | 1.00% | 10 |
| Guix | 0.20% | 2 |
| Other (please specify) | 1.31% | 13 |
| Answered | 996 | |
| Skipped | 421 |
GHCUp and Nix are both continuing their growth as the way folks install Haskell on their system. GHCUp grew a little more than Nix, cementing itself as the most popular individual method. We should thank @hasufell for his work on GHCUp!
| Q18. Has upgrading your Haskell compiler broken your code in the last year? | ||
|---|---|---|
| Answer Choices | Responses | |
| Yes | 27.08% | 264 |
| No | 72.92% | 711 |
| Answered | 975 | |
| Skipped | 442 |
This is great news for the Haskell community! For years this was considered one of the worst aspects of the Haskell ecosystem, it’s fantastic to see improvement in this area. There’s still work to do, of course, but this is the right trajectory. The follow-up question shows that the most common breakage caused by upgrading GHC is imcompatible dependencies. The work on reinstallable base will provide another leap in ease of upgrading GHC.
| Q25. Which build tools do you use for Haskell? | ||
|---|---|---|
| Answer Choices | Responses | |
| Cabal | 83.96% | 738 |
| Stack | 39.59% | 348 |
| Nix | 39.48% | 347 |
| haskell.nix | 10.24% | 90 |
| Buck2 | 2.39% | 21 |
| Make | 7.85% | 69 |
| Shake | 4.55% | 40 |
| ghc-pkg | 2.62% | 23 |
| Bazel | 1.14% | 10 |
| Guix | 0.57% | 5 |
| Other (please specify) | 1.93% | 17 |
| Answered | 879 | |
| Skipped | 538 |
What’s notable here is how Nix has continued to grow, solidifying itself as one of the main tools along with Cabal and Stack.
| Q20. Which versions of GHC do you use? | ||
|---|---|---|
| Answer Choices | Responses | |
| 9.14 | 19.13% | 163 |
| 9.12 | 45.42% | 387 |
| 9.10 | 44.37% | 378 |
| 9.8 | 31.46% | 268 |
| 9.6 | 30.87% | 263 |
| 9.4 | 9.15% | 78 |
| 9.2 | 5.63% | 48 |
| 9.0 | 3.40% | 29 |
| 8.10.x | 6.22% | 53 |
| <8.10 | 3.99% | 34 |
| Answered | 852 | |
| Skipped | 565 |
The shape of this distribution is significantly different than last time, which was bimodal around 9.2 and 8.10 (switching away from 8.10 was difficult for many users). As mentioned before, there’s still work to do in making GHC upgrades easier, but having a unimodal distribution like this is exactly what you’d want to see here.
Haskell Community
| Q34. Where do you interact with the Haskell community? | ||
|---|---|---|
| Answer Choices | Responses | |
| Discourse | 45.59% | 357 |
| 52.62% | 412 | |
| GitHub | 47.51% | 372 |
| Twitter/X | 10.86% | 85 |
| Bluesky | 10.86% | 85 |
| Stack Overflow | 12.90% | 101 |
| Discord | 21.97% | 172 |
| IRC | 11.24% | 88 |
| Mailing lists | 15.58% | 122 |
| Conferences (academic) | 11.88% | 93 |
| Conferences (commercial) | 7.15% | 56 |
| Slack | 9.32% | 73 |
| Telegram | 6.00% | 47 |
| Meetups | 10.73% | 84 |
| Matrix/Riot | 11.62% | 91 |
| Lobsters | 6.90% | 54 |
| Mastodon | 13.03% | 102 |
| Zulip | 2.04% | 16 |
| Gitter | 0.38% | 3 |
| Hacker News | 12.77% | 100 |
| Other (please specify) | 3.96% | 31 |
| Answered | 783 | |
| Skipped | 634 |
Twitter and Stack Overflow both saw large drops, which is not unique to the Haskell Community. Discourse has become the de-facto home of the Haskell community online.
| Q35. Which of the following Haskell topics would you like to see more written about? | ||
|---|---|---|
| Answer Choices | Responses | |
| Best practices | 63.55% | 490 |
| Design patterns | 50.97% | 393 |
| Application architectures | 45.53% | 351 |
| Performance analysis | 46.43% | 358 |
| Debugging how-tos | 33.59% | 259 |
| Production infrastructure | 29.31% | 226 |
| Library walkthroughs | 31.52% | 243 |
| Tooling choices | 26.33% | 203 |
| Case studies | 23.22% | 179 |
| Algorithm implementations | 23.35% | 180 |
| Project maintenance | 16.60% | 128 |
| Web development | 17.90% | 138 |
| GUIs | 20.75% | 160 |
| Testing | 17.64% | 136 |
| Project setup | 14.27% | 110 |
| Beginner fundamentals | 16.21% | 125 |
| Machine learning | 14.53% | 112 |
| Game development | 16.60% | 128 |
| Mobile development | 12.58% | 97 |
| Comparisons to other languages | 11.15% | 86 |
| Other (please specify) | 5.45% | 42 |
| Answered | 771 | |
| Skipped | 646 |
The Haskell Foundation agrees! Best practices are under-documented in the Haskell community. This was actually a big motivation around the program for the Haskell Ecosystem Workshop last year (youtube playlist here).
Final Thoughts
If you’re interested in this sort of thing, I encourage you to take a look at the rest of the publicly available results here, specific subsets of the result will get used by folks like the GHC team in deciding on what work needs prioritization, the Stability Working Group for advocating the categorization of different GHC extensions, and by the HF in deciding how to best support the ecosystem (document best practices, for instance!).
Thank you to those that took part in the survey and I’m excited to see what discussion this inspires.
