Stockfish
Hacker ApprovedThe most recommended of 5 chess engines
Free open-source chess engine that plays stronger than any human and is widely used to analyse games. Critics say its analysis is too strong to teach weaker players and it sometimes gives odd evaluations.
Free open-source chess engine that plays stronger than any human and is widely used to analyse games. Critics say its analysis is too strong to teach weaker players and it sometimes gives odd evaluations.
55 people gave an opinion
- recommend it
- 47
- criticize it
- 8
- approval share
- 85%
Recommended in 9 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 47 people recommend itNeeds 10 or more, met.
- 5.9 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 9 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Stronger than any human or rival engine
“Stockfish is the strongest engine and beats AZ-like implementations like Lc0 and the like.”
Comment from 10 Sep 2026 in “Stockfish 19” “Stockfish is probably stronger, than everything the top labs build.”
Comment from 8 Oct 2026 in ““Math 2.0” will need to value mathematical progress more holistically” “Stockfish has an ELO of 3644[0], compared to Magnus Carlsen at 2882”
Comment from 19 Nov 2025 in “Gemini 3” - Comment from 18 Nov 2025 in “Gemini 3”
- Comment from 19 Nov 2025 in “Blender 5.0”
- Comment from 10 Sep 2026 in “Stockfish 19”
- Comment from 10 Sep 2026 in “Stockfish 19”
Shows best moves for game analysis
“the reason to have Stockfish is not really to play against it, and then inevitably lose, but to use it to show which moves are best”
Comment from 10 Sep 2026 in “Stockfish 19” “I've learned a lot from working through games with stockfish using a git repo and a small script”
Comment from 11 Sep 2026 in “A misalignment of AI in mathematics” “Stockfish finds all of the right (or better moves) in the games from the original paper.”
Comment from 10 Sep 2026 in “Stockfish 19” Steady improvements from a dedicated team
“They tend to have good test harness that can give you an idea of whether the speedups are worth the effort.”
Comment from 20 Apr 2026 in “Can your AI rewrite your code in assembly?” “So, yes, here Stockfish 18 can’t find Rxf2!, but Stockfish 19 does starting at depth 13.”
Comment from 10 Sep 2026 in “Stockfish 19” “Stockfish has by now adopted the best of both worlds and is the better for it”
Comment from 23 Feb 2026 in “What Is a Centipawn Advantage?” - Comment from 10 Sep 2026 in “Stockfish 19”
- Comment from 12 Feb 2026 in “Gemini 3 Deep Think”
- Comment from 10 Sep 2026 in “Stockfish 19”
Strong outside normal chess positions
“It’s oddly fun to put maximum Stockfish in play against some horrible position”
Comment from 10 Sep 2026 in “Stockfish 19” “I'm still surprised that Stockfish is so good in ridiculous scenarios.”
Comment from 6 Nov 2025 in “Show HN: Chess but you make your own starting position” “Stockfish works pretty well outside the normal bounds of chess”
Comment from 14 Feb 2026 in “Show HN: Sameshi – a ~1200 Elo chess engine that fits within 2KB”
What people warn about
Each mark is one comment
Too strong to teach weaker players
“playing vs stockfish does always feel a bit clunky at ~1,700-1,900 ELO”
Comment from 11 May 2026 in “Show HN: I trained a chess engine to play like humans” “analysing with stockfish is _also_ useless, unless you're a super GM.”
Comment from 26 Sep 2026 in “Show HN: A Claude Code skill to analyze your chess games” “practicing against those engines will teach you very little”
Comment from 2 Dec 2025 in “Beej's Guide to Learning Computer Science” Occasional bad reads and odd evaluations
“Evaluation can be way more than just "slightly off" though and can make the evaluation MUCH weaker”
Comment from 28 Feb 2026 in “Show HN: Constrained Chess, Play Stockfish with custom natural-language rules” “Basically this optimization means that stockfish will sometimes take a bad read from a cache”
Comment from 10 Sep 2026 in “Stockfish 19” “It would result in infrequent blunders which however affected my analysis”
Comment from 10 Sep 2026 in “Stockfish 19” - Comment from 10 Sep 2026 in “Stockfish 19”
- Comment from 10 Sep 2026 in “Stockfish 19”
Other chess engines people recommend
The four most recommended other chess engines, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| StockfishThis page | 47 | 8 | 85% | 9 | — | Approved |
| Sameshi chess engine | 10 | 3 | 77% | 1 | — | — |
| Chessmaster 3000 | 6 | 0 | 100% | 3 | — | — |
| Leela Chess Zero | 5 | 0 | 100% | 4 | — | — |
| Regex Chess | 5 | 4 | 56% | 1 | — | — |
What people said
40 of the 61 comments that mention it, newest first. Each links to the original comment.
“Stockfish is probably stronger, than everything the top labs build.”
“analysing with stockfish is _also_ useless, unless you're a super GM.”
“I've learned a lot from working through games with stockfish using a git repo and a small script”
“Stockfish has created entirely new lines in chess which people incorporate into their play.”
“So, yes, here Stockfish 18 can’t find Rxf2!, but Stockfish 19 does starting at depth 13.”
“Stockfish 19 has gotten better at understanding fortresses”
“Showing Black winning in that position is clearly a bug”
“it shows Black is winning with -1.9 eval at depth 32 with SF19”
“Basically this optimization means that stockfish will sometimes take a bad read from a cache”
“It would result in infrequent blunders which however affected my analysis”
“It’s oddly fun to put maximum Stockfish in play against some horrible position”
“Most of the recent chess engines simply implement a neural network (by copying Stockfish)”
“the reason to have Stockfish is not really to play against it, and then inevitably lose, but to use it to show which moves are best”
“Modern Stockfish would annihilate AlphaZero.”
“Stockfish finds all of the right (or better moves) in the games from the original paper.”
“Stockfish is the strongest engine and beats AZ-like implementations like Lc0 and the like.”
“I now lose 100% against 19, probably faster.”
“Was nice to watch the stockfish team methodically improving things.”
“When I enter them into Stockfish now, it usually rates things more similarly to the way AlphaZero did”
“Stockfish took the neural net approach after AlphaZero showed it was a good idea”
“It was very easy (for a grandmaster) vs already super human Stockfish.”
“stockfish, which runs on your 5 year old phone, is dramatically better at chess than Fable”
“Stockfish is a great example of a non-LLM AI that is the best at it's task.”
“If there was any real money in it Stockfish would not be the best chess engine.”
“playing vs stockfish does always feel a bit clunky at ~1,700-1,900 ELO”
“They tend to have good test harness that can give you an idea of whether the speedups are worth the effort.”
“The actual tree search is _incredibly_ sophisticated, with boatloads of heuristics, optimizations, and pruning methods on top of alpha-beta.”
“I think stockfish reasonably qualifies as superhuman AI but not even remotely "general"”
“Evaluation can be way more than just "slightly off" though and can make the evaluation MUCH weaker”
“I don't have a lot of experience with in-depth usage of Stockfish.”
“Stockfish has by now adopted the best of both worlds and is the better for it”
“Stronger players know that Stockfish is relatively better, and by a far margin”
“Stockfish works pretty well outside the normal bounds of chess”
“It found a small but nice little optimization in Stockfish”
“open source specialized models have proven them selves quite nicely actually”
“practicing against those engines will teach you very little”
“Stockfish has an ELO of 3644[0], compared to Magnus Carlsen at 2882”
“Stockfish has beaten commercial chess engines”
“it's incomparably stronger than even the very best humans”
“I'm still surprised that Stockfish is so good in ridiculous scenarios.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.