LeelaChessZero/lc0

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Open source neural network chess engine with GPU acceleration and broad hardware support.

Stars: 3.2k
Forks: 609
Open beginner issues: 0
Indexed issues: 95
Avg merge: 3d 3h
Merged PRs (30d): 10

Dominant language: C++
License: GPL-3.0
Last GitHub push: Sep 19, 2026
Latest indexed: Sep 18, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: good first issue

Beginner friendly Everything

Open All

95 open issues indexed

Inquiry: Pure Swift reimplementation under GPL-3.0 (macOS / MLX) Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#2438 · Opened Aug 6, 2026
Leela Chess Zero (Lc0) Open

Difficulty 5/5 Over a week Newbie friendliness 10/100

LeelaChessZero/lc0#2433 · Opened Jul 26, 2026
[Feature request] Add OpenVINO backend Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

LeelaChessZero/lc0#2419 · Opened Jun 9, 2026
"info ... time" is incorrect. Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

LeelaChessZero/lc0#2418 · Opened Jun 7, 2026
lc0 with ONNX backend has hardcoded cache directories in the binary directory Open

Difficulty 3/5 1-2 days Newbie friendliness 55/100

LeelaChessZero/lc0#2414 · Opened May 19, 2026
Feature request: UCI command or info line to report current weights (.pb) Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2362 · Opened Dec 11, 2025
LC0 compilation BUG on macOS Open

Difficulty 4/5 3-5 days Newbie friendliness 30/100

LeelaChessZero/lc0#2346 · 2 comments · 1 reaction · Opened Nov 16, 2025
LC0 supporting chess variants Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

LeelaChessZero/lc0#2336 · 1 comment · 2 reactions · Opened Nov 1, 2025
Lc0 not presenting Temperature option for UCI protocol Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

LeelaChessZero/lc0#2287 · 2 comments · Opened Sep 12, 2025
lc0 can not load libmkl Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2275 · 6 comments · Opened Sep 1, 2025
--display-cache-usage flag Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

LeelaChessZero/lc0#2261 · 2 comments · Opened Aug 24, 2025
OpenCL GPU support Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#2260 · 5 comments · Opened Aug 23, 2025
LC0 abrupt change of mind (bug ?) Open

blunder

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#2190 · 2 comments · Opened Jun 15, 2025
Save TensorRT engine in weights file for stable performance. Open

enhancement good first issue

Difficulty 4/5 3-5 days Newbie friendliness 45/100

LeelaChessZero/lc0#2185 · 1 comment · Opened Jun 8, 2025
Support for Ceres networks in onnx backend Open

enhancement good first issue

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2180 · Opened Jun 2, 2025
Port "technical" backends to the new API Open

enhancement good first issue

Difficulty 4/5 3-5 days Newbie friendliness 45/100

LeelaChessZero/lc0#2179 · Opened Jun 2, 2025
Enhance `valuehead` search algorithm Open

enhancement good first issue

Difficulty 5/5 Over a week Newbie friendliness 35/100

LeelaChessZero/lc0#2176 · 1 comment · 3 reactions · Opened May 30, 2025
Enhance `policyhead` search algorithm Open

enhancement good first issue

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#2175 · 1 comment · 3 reactions · Opened May 30, 2025
`pip install .` fails with LLVM ERROR: Unsupported stack probing method Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2122 · 5 comments · Opened Feb 8, 2025
Add linux builds to releases Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2105 · 6 comments · 6 reactions · Opened Jan 1, 2025
Update Wiki Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

LeelaChessZero/lc0#2048 · Opened Jul 22, 2024
Support config file with benchmark Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#2043 · 1 comment · Opened Jul 13, 2024
Metal backend doesn't support iOS Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#1926 · 5 comments · 5 reactions · Opened Oct 11, 2023
Idea: Android builds with embedded (built-in) gpu Open

Difficulty 5/5 Over a week Newbie friendliness 18/100

LeelaChessZero/lc0#1857 · Opened Mar 5, 2023
CUBLAS_STATUS_ARCH_MISMATCH error while trying to run Lc0 v0.29 CUDNN backend Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1820 · 5 comments · 1 reaction · Opened Dec 22, 2022
lc0 0.29.0 failed to build on osx Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1814 · 10 comments · Opened Dec 14, 2022
How to compile LC0 on Windows 11 ARM, when using a MacBook Pro M1 MAX and Parallels Desktop? Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#1800 · 11 comments · Opened Nov 29, 2022
Search on a single thread is non-deterministic in 0.29-rc0 with T78 nets Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1769 · 13 comments · Opened Aug 8, 2022
Log when NN eval takes longer than one second. Open

good first issue

Difficulty 3/5 1-2 days Newbie friendliness 35/100

LeelaChessZero/lc0#1768 · 4 comments · Opened Jul 31, 2022
4 Threads on defaults 2 threads with selfplay let xorg crash on non hybrid GPU systems. Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1765 · 4 comments · Opened Jul 24, 2022
Node count goes down when multipv + per-pv-stats is on. Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1763 · Opened Jul 18, 2022
pytorch doesn't like onnx models that leela2onnx produces Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1736 · Opened Apr 21, 2022
ONNX node names should not have leading slash Open

Difficulty 1/5 Under an hour Newbie friendliness 48/100

LeelaChessZero/lc0#1735 · 3 comments · Opened Apr 21, 2022
Extracting parts of Lc0's search into classes would help future development Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#1734 · 5 comments · Opened Apr 20, 2022
512 filter nets does not work with Cuda backend on gtx cards Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#1706 · 1 comment · Opened Mar 7, 2022
Lc0 0.28.2 DirectX 12 - Analysis Bug Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1696 · 6 comments · 1 reaction · Opened Feb 20, 2022
Bad fp16 performance on "GTX 1650" cards Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#1670 · 16 comments · Opened Dec 13, 2021
Demux + multi-stream isn't a well supported situation Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

LeelaChessZero/lc0#1649 · 2 comments · Opened Oct 16, 2021
Some network architectures broken in 0.28 with NaNs in the calculations Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1620 · 10 comments · Opened Aug 5, 2021
The search freezes without apparent reason Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1610 · 1 comment · Opened Jul 23, 2021
Confirm parameter setting with `info string` uci response Open

enhancement good first issue

Difficulty 3/5 1-2 days Newbie friendliness 35/100

LeelaChessZero/lc0#1598 · 9 comments · Opened Jul 1, 2021
Why don't implement LCB algorithm? Open

Difficulty 5/5 Over a week Newbie friendliness 18/100

LeelaChessZero/lc0#1552 · 2 comments · Opened Mar 29, 2021
Make smooth time manager look at best move N in addition to total N Open

LeelaChessZero/lc0#1529 · 1 comment · 1 assignee · Opened Feb 16, 2021
build.sh depends on bash / LS15.0 vs OpenCL on M1 Open

Difficulty 4/5 3-5 days Newbie friendliness 32/100

LeelaChessZero/lc0#1523 · 27 comments · Opened Feb 12, 2021
Unhandled exception: clGetPlatformIDs Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

LeelaChessZero/lc0#1522 · 6 comments · Opened Feb 11, 2021
Improve error checking in time manager options Open

good first issue

Difficulty 3/5 1-2 days Newbie friendliness 35/100

LeelaChessZero/lc0#1480 · 5 comments · Opened Jan 6, 2021
Problems with non-asciil characters in paths Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

LeelaChessZero/lc0#1474 · 2 comments · Opened Dec 16, 2020
LCZero problem or error engines Open

Difficulty 4/5 3-5 days Newbie friendliness 20/100

LeelaChessZero/lc0#1459 · 1 comment · Opened Nov 1, 2020
Investigations of OpenBench for Leela: An Automated Testing Framework Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

LeelaChessZero/lc0#1453 · 1 comment · 4 reactions · Opened Oct 20, 2020
optionsparser_test fails on Mac Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

LeelaChessZero/lc0#1439 · 3 comments · Opened Oct 6, 2020

LeelaChessZero/lc0

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