Mold 2.35.0 â a new release of the high-speed linker
1 points ¡ Open discussionrui314
mold
Rust2020â2026
rui314 / mold
mold
mold đŚ : A Modern Linker in Rust đŚ
80Distinct people
95Mentions
0Explicit recommenders
17.7KGitHub stars
What to know before exploring
What it is
mold đŚ : A Modern Linker in Rust đŚ
GitHub
Where it is used
No documented product use was verified in the last source check.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
- mozilla/sccache ¡ linked in 2 of the same discussions
Mentioned in the same Hacker News threads. That is not proof they are substitutes.
This week on Hacker News
Nov 8âNov 15 UTC ¡ Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 10:01:16 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year95 dated mentions
Observed mentions: 2020-12-13 19:21:00 UTC to 2026-10-05 20:22:21 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repositoryâs dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 2 | 1 | 1 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 15 | 7 | 8 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 34 | 8 | 26 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 20 | 4 | 16 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 9 | 5 | 4 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 8 | 1 | 7 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 7 | 2 | 5 |
From the project README
An excerpt from the repository, fetched Nov 13, 2026.
Read the projectâs introduction
mold: A Modern Linker
mold is a high-performance drop-in replacement for existing Unix linkers,
designed to speed up builds. In our August 2026 benchmarks, it links 4.9x
faster than LLVM lld and 1.9x faster than
wild at the median; see
Benchmark for the full results.
mold is written by the original developer of LLVM lld, the linker that
Android, Chrome, FreeBSD, PlayStation, Nintendo Switch, and other production
systems are built with. mold started as an effort to build an even faster
linker from scratch, free of the architectural limits its author had run into
while optimizing lld. It has been in production use since 2021, and today it
is the default linker of many large open-source projects and is used
internally by many companies.
mold supports x86-64, i386, ARM 32/64, RISC-V 32/64, PowerPC 32/64, s390x,
LoongArch 32/64, SPARC64, m68k, and SH-4.
Why does linking speed matter?
If you are using a compiled language such as C, C++, or Rust, a build consists
of two phases. In the first phase, a compiler compiles source files into
object files (.o files). In the second phase, a linker takes all object
files and combines them into a single executable or shared library file.
The second phase can be time-consuming if your build output is large. mold can
speed up this process, saving you time and preventing distractions while
waiting for a lengthy build to finish. The difference is most noticeable
during rapid debug-edit-rebuild cycles.
Benchmark
Here is a performance comparison of lld, wild, and mold when linking nine
large programs on two machines:
AMD Ryzen Threadripper 7980X (64 cores) running Ubuntu 24.04
Apple M1 Ultra (16 performance cores and 4 efficiency cores) running Fedora
Asahi Remix 42; the benchmark is restricted to the performance cores
The Threadripper represents many-core workstation and server processors, and
the M1 Ultra represents high-performance desktop processors.
All three linkers were built from source in release configuration as of
2026-08-28 and ran with their default options. Times are wall-clock times as
seen by the caller, the median of three runs after a warm-up. The ARM64 rows
are the ARM64 builds of the same programs. The benchmark suite, including all
linker inputs, is available on Zenodo.
AMD Ryzen Threadripper 7980X, debug builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (2.46 GiB)
4.72s
1.98s
0.86s
2.3x
5.5x
Chromium 145 (4.51 GiB)
16.64s
3.98s
1.65s
2.4x
10.1x
Chromium 145 ARM64 (4.76 GiB)
20.91s
N/A
1.83s
N/A
11.4x
Clang 21 (4.19 GiB)
6.19s
3.71s
1.34s
2.8x
4.6x
ClickHouse 26.1 (5.58 GiB)
6.62s
4.40s
0.98s
4.5x
6.7x
Firefox 149 (2.37 GiB)
5.11s
N/A
0.78s
N/A
6.5x
Firefox 149 ARM64 (2.43 GiB)
6.40s
N/A
0.93s
N/A
6.9x
Godot 4.6 (1.01 GiB)
1.77s
1.08s
0.46s
2.3x
3.8x
LibreOffice 26.2 (0.98 GiB)
3.46s
1.41s
0.44s
3.2x
7.9x
PyTorch 2.9 (3.51 GiB)
4.35s
2.48s
0.80s
3.1x
5.4x
TensorFlow 2.21 (9.55 GiB)
50.73s
N/A
3.15s
N/A
16.1x
AMD Ryzen Threadripper 7980X, release builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (0.24 GiB)
0.85s
0.30s
0.20s
1.5x
4.2x
Chromium 145 (0.58 GiB)
6.48s
N/A
0.64s
N/A
10.2x
Chromium 145 ARM64 (0.60 GiB)
7.91s
N/A
0.73s
N/A
10.8x
Clang 21 (0.21 GiB)
0.53s
0.23s
0.11s
2.2x
5.0x
ClickHouse 26.1 (1.23 GiB)
3.18s
2.07s
0.41s
5.0x
7.7x
Firefox 149 (0.22 GiB)
1.01s
0.41s
0.21s
2.0x
4.9x
Godot 4.6 (0.15 GiB)
0.44s
0.21s
0.08s
2.7x
5.8x
LibreOffice 26.2 (0.19 GiB)
1.13s
0.57s
0.19s
3.0x
6.0x
PyTorch 2.9 (0.31 GiB)
0.68s
0.32s
0.15s
2.2x
4.7x
TensorFlow 2.21 (0.73 GiB)
9.62s
N/A
0.70s
N/A
13.7x
Apple M1 Ultra, debug builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (2.46 GiB)
3.21s
1.81s
1.56s
1.2x
2.1x
Chromium 145 (4.51 GiB)
9.54s
3.49s
2.22s
1.6x
4.3x
Chromium 145 ARM64 (4.76 GiB)
12.67s
N/A
2.31s
N/A
5.5x
Clang 21 (4.19 GiB)
4.40s
2.78s
2.96s
0.9x
1.5x
ClickHouse 26.1 (5.58 GiB)
4.92s
3.50s
1.71s
2.1x
2.9x
Firefox 149 (2.37 GiB)
3.21s
N/A
1.12s
N/A
2.9x
Firefox 149 ARM64 (2.43 GiB)
4.13s
N/A
1.12s
N/A
3.7x
Godot 4.6 (1.01 GiB)
1.12s
0.81s
0.62s
1.3x
1.8x
LibreOffice 26.2 (0.98 GiB)
2.08s
0.94s
0.63s
1.5x
3.3x
PyTorch 2.9 (3.51 GiB)
3.07s
2.10s
1.45s
1.4x
2.1x
TensorFlow 2.21 (9.55 GiB)
43.68s
N/A
4.43s
N/A
9.9x
Apple M1 Ultra, release builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (0.24 GiB)
0.56s
0.20s
0.25s
0.8x
2.3x
Chromium 145 (0.58 GiB)
4.25s
N/A
0.78s
N/A
5.5x
Chromium 145 ARM64 (0.60 GiB)
5.17s
N/A
0.91s
N/A
5.7x
Clang 21 (0.21 GiB)
0.30s
0.15s
0.14s
1.0x
2.1x
ClickHouse 26.1 (1.23 GiB)
1.94s
0.95s
0.55s
1.7x
3.5x
Firefox 149 (0.22 GiB)
0.56s
0.23s
0.20s
1.1x
2.7x
Godot 4.6 (0.15 GiB)
0.26s
0.11s
0.11s
1.0x
2.3x
LibreOffice 26.2 (0.19 GiB)
0.62s
0.30s
0.23s
1.3x
2.7x
PyTorch 2.9 (0.31 GiB)
0.43s
0.22s
0.17s
1.3x
2.5x
TensorFlow 2.21 (0.73 GiB)
8.07s
N/A
0.68s
N/A
11.9x
N/A indicates that the linker cannot link that program. wild's Chromium
release links are also marked N/A because wild does not implement --icf=all
and links without identical code folding.
Why is mold so fast?
mold owes its speed to pervasive parallelism and to efficient data structures
and algorithms. For details, read our paper "mold: A Massively Parallel
Linker" (ASPLOS 2027), available at https://arxiv.org/abs/2608.23228.
Installation
Binary packages for the following systems are currently available:
Prebuilt binaries for Linux on x86-64, ARM64, ARM32, RISC-V, PPC64LE, s390x,
and LoongArch are also attached to each
GitHub release.
How to Build
mold is written in Rust and built with Cargo. It requires Rust 1.95 or later;
if your system's Rust is older, install the stable toolchain with
rustup. You also need Git and a C compiler such as GCC or
Clang, which you can install with your system's package manager.
Compile mold
git clone https://github.com/rui314/mold.git
cd mold
cargo build --release
The executable is target/release/mold.
Install mold
Run
Read the full README on GitHubWhat Hacker News says
9 sourcesMold: A Modern Linker (superfast linker)
3 points ¡ Open discussionThe dev who worked on the lld and mold linkers turned the dial to 11...
LLD (part of LLVM):
https://llvm.org/devmtg/2017-10/slides/Ueyama-lld.pdf
MOLD linker:
https://github.com/rui314/mold/blob/main/docs/design.md
Apple released a new linker that's in the same ballpark as mold - see following link for previous discussion - https://news.ycombinator.com/item?id=36218330
In A deep dive into how linkers work (2008)It's not just a problem when you are an amateur. This is sth that every project should provide.
But there are also many projects which do. Sometimes you need to search a bit for it. Actually I would expect that most big projects have such documentation somewhere in some form.
- WebKit: https://github.com/WebKit/WebKit/blob/main/Introduction.md
- Chrome/Chromium: https://www.chromium.org/developers/how-tos/getting-around-t...
- PyTorch: https://github.com/pytorch/pytorch/blob/main/CONTRIBUTING.md...
- RETURNN (my own): https://returnn.readthedocs.io/en/latest/getting_started/tec...
- Mold: https://github.com/rui314/mold/blob/main/docs/design.md
And then for some popular projects you will also find some independent overviews:
- Quake: https://fabiensanglard.net/quake3/ (and many more on https://fabiensanglard.net/)
- Linux: https://tldp.org
Read the rest
/LDP/khg/HyperNews/get/tour/tour.html
- CPython: https://realpython.com/cpython-source-code-guide/
- LLVM: https://blog.regehr.org/archives/1453
One problem is of course that those documents can be outdated and don't go into much details. But they still will give you important insights and should be a good starting point.
Mold 2.32 Released with powerful new features
2 points ¡ Open discussionHave you tried mold [1]? In my experience, it makes a dramatic difference to link times.
[1] https://github.com/rui314/mold/
In Speeding up C++ build timesI think this is unlikely to gain traction. I say that no to discourage you, just to explain.
- The community has an instinctive distrust of closed source or a compiler from an untrusted source. If youâre familiar with the Trusting Trust attack youâll understand why. People wonât send their code to you to compile, because theyâre afraid of it being modified. People wonât use a closed source compiler, when an open source trusted one is available.
- Dev tools in every language ecosystem are almost always free, but sometimes even free tools donât get adopted. Look the experience of the guy who built the mold linker(https://github.com/rui314/mold). Far superior to the state of art, improves incremental compiles a lot, widely applicable across ecosystems (C, C++, Rust), CPU architectures and Operating Systems. You donât even have to modify your
Read the rest
compiler, just need to point to his linker. Heâs even giving it away for free for personal use. But still, almost no one uses it. The inertia of the established options is really high.
- Itâs not complex enough. Think about the complexity involved in the cranelift backend. No one can seriously recreate the efforts of bjorn3. If we could have, we would have. But the idea idea here can be recreated, especially by the experts who already built incremental compilation into rustc.
- But if your solution is truly complex, like the parallel frontend, the burden of maintaining a fork would be too high. Youâd have to spend all your time rebasing.
Again Iâm not trying to discourage you, just stating the difficulties of making a business in the dev tools space. You would be better off contributing this excellent work to the community and trying a different tack.