One language, any hardware. Pythonic syntax. Systems-level performance.

Mojo unifies high-level AI development with low-level systems programming. Write once, deploy everywhere - from CPUs to GPUs - without vendor lock-in.

Power up with Mojo🔥

  • One language, any hardware
  • Bare metal performance
  • Easy to read, Pythonic code
fn add[size: Int](out: LayoutTensor, a:
LayoutTensor, b: LayoutTensor):
    i = global_idx.x
    if i < size:
        out[i] = a[i] + b[i]
def mojo_square_array(array_obj: PythonObject):
    alias simd_width = simdwidthof[DType.int64]()
    ptr = array_obj.ctypes.data.unsafe_get_as_pointer[DType.int64]()
    @parameter
    fn pow[width: Int](i: Int):
        elem = ptr.load[width=width](i)
        ptr.store[width=width](i, elem * elem)
struct VectorAddition:
    @staticmethod
    def execute[target: StaticString](
        out: OutputTensor[rank=1],
        lhs: InputTensor[dtype = out.dtype, rank = out.rank],
        rhs: InputTensor[dtype = out.dtype, rank = out.rank]
        )
        @parameter
        if target == "cpu":
            vector_addition_cpu(out, lhs, rhs)
        elif target == "gpu":
            vector_addition_gpu(out, lhs, rhs)
        else:
            raise Error("No known target:", target)

Efficient element-wise addition of two tensors

Mojo function callable directly from Python

A device-targeted vector addition kernel

Why we built Mojo

  • Vendor lock-in is expensive

    You're forced to choose: NVIDIA's CUDA, AMD's ROCm, or Intel's oneAPI. Rewrite everything when you switch vendors. Your code becomes a hostage to hardware politics.

  • The two-language tax

    Prototype in Python. Rewrite in C++ for production. Debug across language boundaries. Your team splits into 'researchers' and 'engineers' - neither can work on the full stack.

  • Python hits a wall

    Python is 1000x too slow for production AI. The GIL blocks true parallelism. Can't access GPUs directly. Every optimization means dropping into C extensions. Simplicity becomes a liability at scale.

  • Toolchain chaos

    PyTorch for training. TensorRT for inference. vLLM for serving. Each tool has its own bugs, limitations, and learning curve. Integration nightmares multiply with every component.

  • Memory bugs in production

    C++ gives you footguns by default. Race conditions in parallel code. Memory leaks that OOM your servers. Segfaults in production at 3 AM.

  • Developer experience ignored

    30-minute build times. Cryptic template errors. Debuggers that can't inspect GPU state. Profilers that lie about performance. Modern developers deserve tools that accelerate, not frustrate.

Why should I use Mojo?

  • Easier

    GPU Programming Made Easy

    Traditionally, writing custom GPU code means diving into CUDA, managing memory, and compiling separate device code. Mojo simplifies the whole experience while unlocking top-tier performance on NVIDIA and AMD GPUs.

    @parameter
    for n_mma in range(num_n_mmas):
        alias mma_id = n_mma * num_m_mmas + m_mma
    
        var mask_frag_row = mask_warp_row + m_mma * MMA_M
        var mask_frag_col = mask_warp_col + n_mma * MMA_N
    
        @parameter
        if is_nvidia_gpu():
            mask_frag_row += lane // (MMA_N // p_frag_simdwidth)
            mask_frag_col += lane * p_frag_simdwidth % MMA_N
        elif is_amd_gpu():
            mask_frag_row += (lane // MMA_N) * p_frag_simdwidth
            mask_frag_col += lane % MMA_N
    

    GPU-specific coordinates for MMA tile processing

  • PERFORMANT

    Bare metal performance on any GPU

    Get raw GPU performance without complex toolchains. Mojo makes it easy to write high-performance kernels with intuitive syntax, zero boilerplate, and native support for NVIDIA, AMD, and more.

    @parameter
    for i in range(K):
        var reduced = top_k_sram[tid]
        alias limit = log2_floor(WARP_SIZE)
        
        @parameter
        for j in reversed(range(limit)):
            alias offset = 1 << j
            var shuffled = TopKElement(
                warp.shuffle_down(reduced.idx, offset),
                warp.shuffle_down(reduced.val, offset),
            )
            reduced = max(reduced, shuffled)
        
        barrier()
    

    Using low level warp GPU instructions ergonomically

  • InteroperabLE

    Use Mojo to extend python

    Mojo interoperates natively with Python so you can speed up bottlenecks without rewriting everything. Start with one function, scale as needed—Mojo fits into your codebase

    if __name__ == "__main__":
        # Calling into a Mojo `passthrough` function from Python:
        result = hello_mojo.passthrough("Hello")
        print(result)
    
    fn passthrough(value: PythonObject) raises -> PythonObject:
        """A very basic function illustrating passing values to and from Mojo."""
        return value + " world from Mojo"
    

    Call a Mojo function from Python

  • Community

    Build with us in the open to create the future of AI

    Mojo has more than  750K+ lines of open-source code with an active community of 50K+ members. We're actively working to open even more to build a transparent, developer-first foundation for the future of AI infrastructure.

    750k

    lines of open-source code

  • MOJO + MAX

    Write GPU Kernels with MAX

    Traditionally, writing custom GPU code means diving into CUDA, managing memory, and compiling separate device code. Mojo simplifies the whole experience while unlocking top-tier performance on NVIDIA and AMD GPUs.

    @compiler.register("mo.sub")
    struct Sub:
        @staticmethod
        fn execute[
            target: StaticString,
            _trace_name: StaticString,
        ](
            z: FusedOutputTensor,
            x: FusedInputTensor,
            y: FusedInputTensor,
            ctx: DeviceContextPtr,
        ) capturing raises:
            @parameter
            @always_inline
            fn func[width: Int](idx: IndexList[z.rank]) -> SIMD[z.dtype, width]:
                var lhs = rebind[SIMD[z.dtype, width]](x._fused_load[width](idx))
                var rhs = rebind[SIMD[z.dtype, width]](y._fused_load[width](idx))
                return lhs - rhs
            
            foreach[
                func,
                target=target,
                _trace_name=_trace_name,
            ](z, ctx)
    

    Define a custom GPU subtraction kernel

  • InteroperabLE

    Powering Breakthroughs in Production AI

    Top AI teams use Mojo to turn ideas into optimized, low-level GPU code. From Inworld’s custom logic to Qwerky’s memory-efficient Mamba, Mojo delivers where performance meets creativity.

  • PERFORMANT

    World-Class Tools, Out of the Box

    Mojo ships with a great VSCode debugger and works with dev tools like Cursor and Claude. Mojo makes modern dev workflows feel seamless.

    Mojo extension in VSCode

Mojo learns from

    • What Mojo keeps from C++

      • Zero cost abstractions

      • Metaprogramming power

        Turing complete: can build a compiler in templates

      • Low level hardware control

        Inline asm, intrinsics, zero dependencies

      • Unified host/device language

    • What Mojo improves about C++

      • Slow compile times

      • Template error messages

      • Limited metaprogramming

        ...and that templates != normal code

      • Not MLIR-native

    • What Mojo keeps from Python

      • Minimal boilerplate

      • Easy-to-read syntax

      • Interoperability with the massive Python ecosystem

    • What Mojo improves about Python

      • Performance

      • Memory usage

      • Device portability

    • What Mojo keeps from Rust

      • Memory safety through borrow checker

      • Systems language performance

    • What Mojo improves about Rust

      • More flexible ownership semantics

      • Easier to learn

      • More readable syntax

    • What Mojo keeps from Zig

      • Compile-time metaprogramming

      • Systems language performance

    • What Mojo improves about Zig

      • Memory safety

      • More readable syntax

“Mojo has Python feel, systems speed. Clean syntax, blazing performance.”

Explore the world of high-performance computing through an illustrated comic. A fresh, fun take—whether you're new or experienced.

Read the comic

Get started with Mojo

  • Mojo Manual

    Learn how to write a simple program that performs vector addition on a GPU, exploring fundamental concepts of GPU programming.

  • GPU Puzzles

    A hands-on guide to mastering GPU programming  using Mojo’s powerful abstractions and performance capabilities.

  • Python Interoperability

    Because Mojo uses a Pythonic syntax, its easy to start reading and writing Mojo when coming from Python

Popular Mojo Tech Talks

  • Next-Gen GPU Programming

    1:15:56

  • Kernel Programming and Mojo

    52:51

  • GPU Programming Workshop

    11:36

Developer Approved

potential to take over

svpino

“A few weeks ago, I started learning Mojo 🔥 and MAX. Mojo has the potential to take over AI development. It's Python++. Simple to learn, and extremely fast.”

very excited

strangemonad

“I'm very excited to see this coming together and what it represents, not just for MAX, but my hope for what it could also mean for the broader ecosystem that mojo could interact with.”

feeling of superpowers

Aydyn

"Mojo gives me the feeling of superpowers. I did not expect it to outperform a well-known solution like llama.cpp."

one language all the way through

fnands

“Tired of the two language problem. I have one foot in the ML world and one foot in the geospatial world, and both struggle with the 'two-language' problem. Having Mojo - as one language all the way through is be awesome.”

was a breeze!

NL

“Max installation on Mac M2 and running llama3 in (q6_k and q4_k) was a breeze! Thank you Modular team!”

works across the stack

scrumtuous

“Mojo can replace the C programs too. It works across the stack. It’s not glue code. It’s the whole ecosystem.”

amazing achievements

Eprahim

“I'm excited, you're excited, everyone is excited to see what's new in Mojo and MAX and the amazing achievements of the team at Modular.”

actually flies on the GPU

Sanika

"after wrestling with CUDA drivers for years, it felt surprisingly… smooth. No, really: for once I wasn’t battling obscure libstdc++ errors at midnight or re-compiling kernels to coax out speed. Instead, I got a peek at writing almost-Pythonic code that compiles down to something that actually flies on the GPU."

impressive speed

Adalseno

"It worked like a charm, with impressive speed. Now my version is about twice as fast as Julia's (7 ms vs. 12 ms for a 10 million vector; 7 ms on the playground. I guess on my computer, it might be even faster). Amazing."

surest bet for longterm

pagilgukey

“Mojo and the MAX Graph API are the surest bet for longterm multi-arch future-substrate NN compilation”

impressed

justin_76273

“The more I benchmark, the more impressed I am with the MAX Engine.”

easy to optimize

dorjeduck

“It’s fast which is awesome. And it’s easy. It’s not CUDA programming...easy to optimize.”

pure iteration power

Jayesh

"This is about unlocking freedom for devs like me, no more vendor traps or rewrites, just pure iteration power. As someone working on challenging ML problems, this is a big thing."

The future is bright!

mytechnotalent

Mojo destroys Python in speed. 12x faster without even trying. The future is bright!

Community is incredible

benny.n

“The Community is incredible and so supportive. It’s awesome to be part of.”

huge increase in performance

Aydyn

"C is known for being as fast as assembly, but when we implemented the same logic on Mojo and used some of the out-of-the-box features, it showed a huge increase in performance... It was amazing."

high performance code

jeremyphoward

"Mojo is Python++. It will be, when complete, a strict superset of the Python language. But it also has additional functionality so we can write high performance code that takes advantage of modern accelerators."

completely different ballgame

scrumtuous

“What @modular is doing with Mojo and the MaxPlatform is a completely different ballgame.”

12x faster without even trying

svpino

“Mojo destroys Python in speed. 12x faster without even trying. The future is bright!”

performance is insane

drdude81

“I tried MAX builds last night, impressive indeed. I couldn't believe what I was seeing... performance is insane.”

Get started with Mojo

View Documentation
  • Get started guide

    Install MAX with a few commands and deploy a GenAI model locally.

    Read Guide
  • Browse open models

    500+ models, many optimized for lightning-fast performance

    Browse models