> For the complete Mojo documentation index, see [llms.txt](/llms.txt).
> Markdown versions of all pages are available by appending .md to any URL (e.g. /docs/manual/basics.md).

# Mojo standard library

<!-- here only for Listing component -->

All the data types, structs, traits, functions, and other APIs included with Mojo.

The standard library provides nearly everything you'll need for
writing Mojo programs, including basic data types like
[`Int`](/docs/std/builtin/int/Int/) and
[`SIMD`](/docs/std/builtin/simd/SIMD/), collection types like
[`List`](/docs/std/collections/list/List/), reusable
[algorithms](/docs/std/algorithm/), and modules to support
[GPU programming](/docs/std/gpu/).

## Packages

* [`algorithm`](/docs/std/algorithm/): High performance data operations: vectorization, parallelization, reduction, memory.
* [`atomic`](/docs/std/atomic/): Atomic operations and memory orderings.
* [`base64`](/docs/std/base64/): Binary data encoding: base64 and base16 encode/decode functions.
* [`benchmark`](/docs/std/benchmark/): Performance benchmarking: statistical analysis and detailed reports.
* [`bit`](/docs/std/bit/): Bitwise operations: manipulation, counting, rotation, and power-of-two utilities.
* [`builtin`](/docs/std/builtin/): Language foundation: built-in types, traits, and fundamental operations.
* [`collections`](/docs/std/collections/): Core data structures: List, Dict, Set, Optional, plus specialized collections.
* [`compile`](/docs/std/compile/): Runtime function compilation and introspection: assembly, IR, linkage, metadata.
* [`complex`](/docs/std/complex/): Complex numbers: SIMD types, scalar types, and operations.
* [`documentation`](/docs/std/documentation/): Documentation built-ins: decorators and utilities for doc generation.
* [`ffi`](/docs/std/ffi/): Foreign function interface (FFI) for calling C code and loading libraries.
* [`format`](/docs/std/format/): Provides formatting traits for converting types to text.
* [`gpu`](/docs/std/gpu/): GPU programming primitives: thread blocks, async memory, barriers, and sync.
* [`hashlib`](/docs/std/hashlib/): Cryptographic and non-cryptographic hashing with customizable algorithms.
* [`io`](/docs/std/io/): Core I/O operations: console input/output, file handling, writing traits.
* [`iter`](/docs/std/iter/): Iteration traits and utilities: Iterable, IterableOwned, Iterator, enumerate, zip, map.
* [`itertools`](/docs/std/itertools/): Iterator tools for lazy sequence generation and transformation.
* [`logger`](/docs/std/logger/): Logging with configurable severity levels.
* [`math`](/docs/std/math/): Math functions and constants: trig, exponential, logarithmic, and special functions.
* [`memory`](/docs/std/memory/): Low-level memory management: pointers, allocations, address spaces.
* [`os`](/docs/std/os/): OS interface layer: environment, filesystem, process control.
* [`pathlib`](/docs/std/pathlib/): Filesystem path manipulation and navigation.
* [`prelude`](/docs/std/prelude/): Standard library prelude: fundamental types, traits, and operations auto-imported.
* [`pwd`](/docs/std/pwd/): Password database lookups for user account information.
* [`python`](/docs/std/python/): Python interoperability: import packages and modules, call functions, type conversion.
* [`random`](/docs/std/random/): Pseudorandom number generation with uniform and normal distributions.
* [`reflection`](/docs/std/reflection/): Compile-time reflection utilities for introspecting Mojo types and functions.
* [`runtime`](/docs/std/runtime/): Runtime services: async execution and program tracing.
* [`stat`](/docs/std/stat/): File type constants and detection from stat system calls.
* [`subprocess`](/docs/std/subprocess/): Execute external processes and commands.
* [`sys`](/docs/std/sys/): System runtime: I/O, hardware info, intrinsics, compile-time utils.
* [`tempfile`](/docs/std/tempfile/): Manage temporary files and directories: create, locate, and cleanup.
* [`testing`](/docs/std/testing/): Unit testing: Assertions (equal, true, raises) and test suites.
* [`time`](/docs/std/time/): Timing operations: monotonic clocks, performance counters, sleep, time_function.
* [`utils`](/docs/std/utils/): General utils: indexing, variants, static tuples, and thread synchronization.