zfp consists of four distinct parts: a compression library written in C, a set of C++ header files that implement compressed arrays and corresponding C wrappers, optional Python and Fortran bindings, and a set of C and C++ examples and utilities. The main compression codec is written in C and should conform to both the ISO C89 and C99 standards. The C++ array classes are implemented entirely in header files and can be included as is, but since they call the compression library, applications must link with libzfp.

zfp is preferably built using CMake, although the core library can also be built using GNU make on Linux, macOS, and MinGW. zfp has successfully been built and tested using these compilers:

  • gcc versions 4.4.7, 4.7.3, 4.8.5, 4.9.4, 5.5.0, 6.1.0, 6.4.0, 7.1.0, 7.3.0, 8.1.0
  • icc versions 14.0.3, 15.0.6, 16.0.4, 17.0.2, 18.0.2, 19.0.3
  • clang versions 3.9.1, 4.0.0, 5.0.0, 6.0.0
  • MinGW version 5.3.0
  • Visual Studio versions 14 (2015), 15 (2017)

zfp conforms to various language standards, including C89, C99, C++98, C++11, and C++14.


zfp requires 64-bit compiler and operating system support.

CMake Builds

To build zfp using CMake on Linux or macOS, start a Unix shell and type:

cd zfp-0.5.5
mkdir build
cd build
cmake ..

To also build the examples, replace the cmake line with:


By default, CMake builds will attempt to locate and use OpenMP. To disable OpenMP, type:


To build zfp using Visual Studio on Windows, start a DOS shell and type:

cd zfp-0.5.5
mkdir build
cd build
cmake ..
cmake --build . --config Release

This builds zfp in release mode. Replace ‘Release’ with ‘Debug’ to build zfp in debug mode. See the instructions for Linux on how to change the cmake line to also build the example programs.

GNU Builds

To build zfp using gcc without OpenMP, type:

cd zfp-0.5.5

This builds libzfp as a static library as well as the zfp command-line utility. To enable OpenMP parallel compression, type:



GNU builds expose only limited functionality of zfp. For instance, CUDA and Python support are not included. For full functionality, build zfp using CMake.


To test that zfp is working properly, type:


or using GNU make:

gmake test

If the GNU build or regression tests fail, it is possible that some of the macros in the file Config have to be adjusted. Also, the tests may fail due to minute differences in the computed floating-point fields being compressed, which will be indicated by checksum errors. If most tests succeed and the failures result in byte sizes and error values reasonably close to the expected values, then it is likely that the compressor is working correctly.

Build Targets

To specify which components to build, set the macros below to ON (CMake) or 1 (GNU make), e.g.,


or using GNU make


Regardless of the settings below, libzfp will always be built.


Build all subdirectories; enable all options (except BUILD_SHARED_LIBS). Default: off.


Build libcfp for C bindings to compressed arrays. Default: off.


Build zfPy for Python bindings to the C API.

CMake will attempt to automatically detect the Python installation to use. If CMake finds multiple Python installations, it will use the newest one. To specify a specific Python installation to use, set PYTHON_LIBRARY and PYTHON_INCLUDE_DIR on the cmake line:

cmake -DBUILD_ZFPY=ON -DPYTHON_LIBRARY=/path/to/lib/ -DPYTHON_INCLUDE_DIR=/path/to/include/python2.7 ..

CMake default: off. GNU make default: off and ignored.


Build libzFORp for Fortran bindings to the C API. Requires Fortran standard 2003 or later. GNU make users may specify the Fortran compiler to use via

gmake BUILD_ZFORP=1 FC=/path/to/fortran-compiler

Default: off.


Build zfp command-line utility for compressing binary files. Default: on.


Build code examples. Default: off.


Build testzfp and (when on the GitHub develop branch) unit tests. Default: on.


Build shared objects (.so, .dylib, or .dll files). On macOS, the SOFLAGS line in the Config file may have to be uncommented when building with GNU make. CMake default: on. GNU make default: off.


The behavior of zfp can be configured at compile time via a set of macros in the same manner that build targets are specified, e.g.,


64-bit signed and unsigned integer types and their literal suffixes. Platforms on which long int is 32 bits wide may require long long int as type and ll as suffix. These macros are relevant only when compiling in C89 mode. When compiling in C99 mode, integer types are taken from stdint.h. Defaults: long int, l, unsigned long int, and ul, respectively.


CMake and GNU make macro for enabling or disabling OpenMP support. CMake builds will by default enable OpenMP when available. Set this macro to 0 or OFF to disable OpenMP support. For GNU builds, OpenMP is disabled by default. Set this macro to 1 or ON to enable OpenMP support. See also OMPFLAGS in Config in case the compiler does not recognize -fopenmp. NOTE: clang currently does not support OpenMP on macOS. CMake default: on. GNU make default: off.


CMake macro for enabling or disabling CUDA support for GPU compression and decompression. When enabled, CUDA and a compatible host compiler must be installed. For a full list of compatible compilers, please consult the NVIDIA documentation. If a CUDA installation is in the user’s path, it will be automatically found by CMake. Alternatively, the CUDA binary directory can be specified using the CUDA_BIN_DIR environment variable. CMake default: off. GNU make default: off and ignored.


Use aligned memory allocation in an attempt to align compressed blocks on hardware cache lines. Default: undefined/off.


Use a two-way skew-associative rather than direct-mapped cache. This incurs some overhead that may be offset by better cache utilization. Default: undefined/off.


Use a simpler hash function for cache line lookup. This is faster but may lead to more collisions. Default: undefined/off.


Enable cache profiling to gather and print statistics on cache hit and miss rates. Default: undefined/off.


Unsigned integer type used for buffering bits. Wider types tend to give higher performance at the expense of lower bit rate granularity. For portability of compressed files between little and big endian platforms, BIT_STREAM_WORD_TYPE should be set to uint8. Default: uint64.


CMake macro for indirectly setting BIT_STREAM_WORD_TYPE. Valid values are 8, 16, 32, 64. Default: 64.


Enable support for strided bit streams that allow for non-contiguous memory layouts, e.g., to enable progressive access. Default: undefined/off.


Macro for renaming the outermost cfp namespace, e.g., to avoid name clashes. Default: cfp.


Path to the Python library, e.g., /usr/lib/ CMake default: undefined/off. GNU make default: off and ignored.


Path to the Python include directory, e.g., /usr/include/python2.7. CMake default: undefined/off. GNU make default: off and ignored.


The core zfp library and compressed arrays require only a C89 and C++98 compiler. The optional components have additional dependencies, as outlined in the sections below.


CMake builds require version 3.1 or later on Linux and macOS and version 3.4 or later on Windows. CMake is available here.


CUDA support requires CMake and a compatible host compiler (see ZFP_WITH_CUDA).


The optional Python bindings require CMake and the following minimum versions:

  • Python: Python 2.7 & Python 3.5
  • Cython: 0.22
  • NumPy: 1.8.0

The necessary dependencies can be installed using pip and the zfp requirements.txt:

pip install -r $ZFP_ROOT/python/requirements.txt


The optional Fortran bindings require a Fortran 2003 compiler.