Stockfish (projet + apps officielles) review: scores and evidence
An open-source UCI engine (Stockfish 18, 31/01/2026), listed with its Mac and iOS apps on the download page and developed by a community (Discord with 12,286 members, fishtest). It evaluates positions; it imports nothing, explains nothing and offers no training.
Read on August 30, 2026 from the service’s public pages — every score cites the page read.
Overall score
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Not scored overall
Rank
—
Languages
2
Listed price
€0 (GPL v3; "Stockfish Chess" Mac app free; SmallFish iOS $4.99 ≈ €4.59)
What the service is
Stockfish is a free chess engine (GPL v3 licence) developed and maintained by a community of contributors within the official-stockfish GitHub organisation (https://github.com/official-stockfish/Stockfish). According to the site’s "About" page (https://stockfishchess.org/about/), it was born in November 2008 when Marco Costalba forked Glaurung 2.1, Tord Romstad’s engine, with Romstad and Joona Kiiski joining afterwards. The project publishes binaries for Windows, Linux, macOS and Android, to be chosen according to the processor’s instruction set, and its download page (https://stockfishchess.org/download/) points to two third-party apps: "Stockfish Chess" on Mac, free, by Daylen Yang (https://apps.apple.com/us/app/stockfish-chess/id801463932), and "SmallFish" on iOS, $4.99, by Ted Wong (https://apps.apple.com/us/app/smallfish-chess-for-stockfish/id675049147). What the engine does: evaluate a position and compute the best moves over the UCI protocol, using an NNUE neural network and Syzygy tablebases; every change is validated through public statistical tests on Fishtest. Business model: free, with no account or subscription, and the site collects no data. As the repository itself points out, Stockfish is not a complete chess program: it has no graphical interface, imports no games, explains no mistakes and offers no exercises, courses or play against humans. The latest major release, Stockfish 18, is dated 31 January 2026 (https://stockfishchess.org/blog/2026/stockfish-18/).
Activity history
- 2026-08Version 19.4.0 of the SmallFish iOS app (Ted Wong, $4.99, 4.8/5 from about 4,500 ratings) released at the end of August 2026 ("1 day ago" on the listing consulted on 1 September 2026) — https://apps.apple.com/us/app/smallfish-chess-for-stockfish/id675049147.
- 2026-01Stockfish 18 released on 31 January 2026: an advertised gain of "up to 46 points" of ELO over Stockfish 17, the SFNNv10 network with threat inputs, shared memory for network weights across processes, and reproducible training on more than 100 billion Lc0 positions — https://stockfishchess.org/blog/2026/stockfish-18/.
- 2025-03Stockfish 17.1 released on 30 March 2025 — https://stockfishchess.org/blog/.
- 2024-09Stockfish 17 released on 6 September 2024 — https://stockfishchess.org/blog/.
- 2024-02Stockfish 16.1 released on 24 February 2024 — https://stockfishchess.org/blog/.
- 2023-06Stockfish 16 released on 30 June 2023, advertised at up to 50 ELO points above the previous version — https://stockfishchess.org/blog/.
- 2022-12Stockfish 15.1 released on 4 December 2022, with version 5 of the NNUE architecture — https://stockfishchess.org/blog/.
- 2008-11In November 2008 Marco Costalba forked Tord Romstad’s Glaurung 2.1 and published the first Stockfish version; Romstad and Joona Kiiski joined the project afterwards — https://stockfishchess.org/about/.
The scores, evidence by evidence
Every score points to the page read and the fact found there. A fact documented nowhere is not credited: document it, then write to us.
APersonalized diagnosis
0.4A1 :0Importing your games (Chess.com, Lichess, PGN files)
https://stockfishchess.org/download/: UCI engine, no account import; SmallFish loads games (App Store) without a Lichess/Chess.com connection
A2 :1Automatic engine analysis of every game
apps.apple.com id675049147 (SmallFish): "review your game", "Blunder checking"; automatic pass not documented
A3 :0Recurring mistakes identified across all your games
https://stockfishchess.org/: no aggregation
A4 :0Types of mistakes covered (tactics, strategy, endgame, time…)
https://stockfishchess.org/: no typology
A5 :0Written explanation of each mistake
https://stockfishchess.org/: numerical evaluation only
A6 :0Stated verification of the diagnoses (procedure, rates)
no mention on https://stockfishchess.org/
A7 :0Tracking each weakness over time
no history on https://stockfishchess.org/
A8 :0Comparison with players of the same rating
no comparison on https://stockfishchess.org/
BOpenings
0.0B1 :0Building a personal repertoire
no repertoire on https://stockfishchess.org/
B2 :0Training the repertoire (drills, games)
no drill on https://stockfishchess.org/
B3 :0Spotting where you left your repertoire in your games
no mention on https://stockfishchess.org/
B4 :0Verification of the lines taught (engine, practice)
no information on https://stockfishchess.org/
B5 :0Opening explorer and statistics
no explorer on https://stockfishchess.org/ (SmallFish opening books only)
B6 :0Explanation of opening plans and ideas
no teaching on https://stockfishchess.org/
CTargeted training
0.0C1 :0Exercises drawn from your own games
no exercises on https://stockfishchess.org/
C2 :0Bank of tactical exercises (size, themes, rating)
no bank on https://stockfishchess.org/
C3 :0Endgame training
apps.apple.com id675049147: "Endgame tablebase" only, no module
C4 :0Strategic and positional training
https://stockfishchess.org/: no exercises
C5 :0Training defense and alertness
https://stockfishchess.org/: no exercises
C6 :0Training calculation and visualization
no mention on https://stockfishchess.org/
C7 :0Difficulty matched to your real level
no rating on https://stockfishchess.org/
C8 :0Spaced repetition (named algorithm)
https://stockfishchess.org/: no repetition
C9 :0Personalized training plan
https://stockfishchess.org/: no plan
DPrice and value
10.0D1 :3What the free plan actually lets you do
https://stockfishchess.org/: "Free, open-source"; free Mac app
D2 :3Annual price of the full plan
https://stockfishchess.org/: €0 (SmallFish $4.99 one-off)
D3 :3Commercial transparency (price shown, trial, cancellation)
https://stockfishchess.org/: free, no subscription
D4 :3Number of paid tiers (how simple the offer is)
https://stockfishchess.org/download/: free engine; SmallFish $4.99 one-off purchase with no in-app purchases
EEvidence and transparency
7.5E1 :0Published evidence of effectiveness
no effectiveness data on https://stockfishchess.org/
E2 :3Chess verification of the content (positions, lines)
https://github.com/official-stockfish/Stockfish: public fishtest tests (SPRT) for every change
E3 :3Transparency of the method (algorithms, code)
https://github.com/official-stockfish/Stockfish: GPL v3 source code
E4 :3Marketing claims that can be checked (no overselling)
https://github.com/official-stockfish/Stockfish: "not a complete chess program and requires a UCI-compatible GUI" (stated limitation)
FContent and method
0.0F1 :0Courses organized by rating level
no courses on https://stockfishchess.org/
F2 :0Course authors named and titled
no content author on https://stockfishchess.org/
F3 :0Content formats (text, video, interactive)
no content on https://stockfishchess.org/
F4 :0Published method of progression
no method on https://stockfishchess.org/
F5 :0How often the content is updated
no teaching content; engine releases only (https://stockfishchess.org/blog/)
GPlaying and practice
1.7G1 :0Playing humans online (pool, anti-cheating)
no play against humans on https://stockfishchess.org/
G2 :1Realistic artificial opponents
apps.apple.com id801463932: "Play two-player games"; level limiting not verified today
G3 :1Replaying one specific position against the machine
apps.apple.com id801463932: "copy and paste FEN strings"; play from an entered position
G4 :0Tournaments and organized competition
no tournaments on https://stockfishchess.org/
HExperience and accessibility
6.0H1 :2Platforms available (web, iOS, Android, desktop)
https://stockfishchess.org/download/: Windows/Linux/macOS/Android + Mac App Store + iOS SmallFish; no web version
H2 :3User ratings and reviews (stores, press)
apps.apple.com id675049147: SmallFish 4.78/5, 4 466 ratings
H3 :1Interface languages available
at least two languages (French interface observed, total number not recorded) — apps.apple.com id675049147: languages including FR; command-line engine
H4 :0Accessibility (keyboard, screen reader)
no accessibility information on https://stockfishchess.org/
H5 :3Offline use and known incidents
https://stockfishchess.org/download/: local software
IPreparation and study
2.5I1 :0Preparing for a named opponent
https://stockfishchess.org/download/: no opponent preparation
I2 :1Annotating and sharing games (studies)
https://apps.apple.com/us/app/stockfish-chess/id801463932: annotated variations, PGN; no sharing by link
I3 :1Entering a game played at a club (photo, scoresheet)
https://apps.apple.com/us/app/smallfish-chess-for-stockfish/id675049147: "setup board" and FEN; no scanning
I4 :1Searching your games (filters, position)
https://apps.apple.com/us/app/smallfish-chess-for-stockfish/id675049147: database of loaded games, no documented filter
JHuman coaching and community
3.3J1 :0Access to human coaches
no coach on https://stockfishchess.org/
J2 :2Size and activity of the community
discord.com/api/invites/GWDRS3kU6R: "Stockfish" server, 12 286 members; fishtest 2 226 testers (chessprogramming.org/Stockfish)
J3 :0Tools for trainers, clubs and schools
no coach tools on https://stockfishchess.org/
J4 :2Engagement mechanics (streaks, virtual currency, reminders)
https://stockfishchess.org/: no engagement mechanics
KPersonal data and interoperability
5.6K1 :0Exporting your data (games, repertoire)
https://stockfishchess.org/: no user data stored, no export
K2 :2Protection of personal data (GDPR, hosting)
https://stockfishchess.org/download/: local software; SmallFish "no data tracking" (App Store)
K3 :3Public API and source code
https://github.com/official-stockfish/Stockfish: GPL v3, UCI protocol
Also, outside the grid
Features found that no criterion measures. They do not count towards the score.
- Syzygy endgame tablebases
- Direct Lichess/Chess.com import (SmallFish)
- Blunder checking (SmallFish)
- Binaries per CPU instruction set
Sources consulted
- https://github.com/official-stockfish/Stockfish
- https://stockfishchess.org/about/
- https://stockfishchess.org/download/
- https://apps.apple.com/us/app/stockfish-chess/id801463932
- https://apps.apple.com/us/app/smallfish-chess-for-stockfish/id675049147
- https://stockfishchess.org/blog/2026/stockfish-18/
- https://stockfishchess.org/blog/
- https://stockfishchess.org/
Services with a similar profile
The three services whose category profile is closest — a distance over the eleven scores, computed, never chosen.