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Build Status Tests Stable

Binn is a binary data serialization format designed to be compact, fast and easy to use.


The elements are stored with their sizes to increase the read performance.

The library uses zero-copy when reading strings, blobs and containers.

The strings are null terminated so when read the library returns a pointer to them inside the buffer, avoiding memory allocation and data copying.

Data Types

The Binn format supports all these:

Primitive data types:

  • null
  • boolean (true and false)
  • integer (up to 64 bits signed or unsigned)
  • floating point numbers (IEEE single and double precision)
  • string
  • blob (binary data)
  • user defined


  • list
  • map (numeric key associative array)
  • object (text key associative array)


The elements are stored in this way:

boolean, null:

int, float (storage: byte, word, dword or qword):

string, blob:

list, object, map:

Example Structure

A json data such as {"hello":"world"} is serialized in binn as:

  \xE2           // type = object (container)
  \x11           // container total size
  \x01           // key/value pairs count
  \x05hello      // key
  \xA0           // type = string
  \x05world\x00  // value (null terminated)

You can check the complete specification

Usage Example


binn *obj;

// create a new object
obj = binn_object();

// add values to it
binn_object_set_int32(obj, "id", 123);
binn_object_set_str(obj, "name", "John");
binn_object_set_double(obj, "total", 2.55);

// send over the network or save to a file...
send(sock, binn_ptr(obj), binn_size(obj));

// release the buffer


int id;
char *name;
double total;

id = binn_object_int32(obj, "id");
name = binn_object_str(obj, "name");
total = binn_object_double(obj, "total");

More examples

You can find more usage examples here and in the examples folder

Other Implementations

Feel free to make a wrapper for your preferred language. Then inform us so we can list it here.

How to use

  1. Including the binn.c file in your project; or
  2. Including the static library in your project; or
  3. Linking to the binn library:

On Linux and MacOSX:

gcc myapp.c -lbinn

On Windows:

Include the binn-3.0.lib in your MSVC project or use MinGW:

gcc myapp.c -lbinn-3.0

Compiling the Library

On Linux and MacOSX:

git clone
cd binn
sudo make install

It will create the file on Linux and libbinn.3.dylib on MacOSX

On Windows:

Use the included Visual Studio project in the src/win32 folder or compile it using MinGW:

git clone
cd binn

Both will create the file binn-3.0.dll

Static library

To generate a static library:

make static

It will create the file libbinn.a

On Android:

Check for pre-compiled binaries in the android-binn-native project

Regression Tests

On Linux, MacOSX and Windows (MinGW):

cd binn
make test

On Windows (Visual Studio):

Use the included project in the test/win32 folder


The current version (3.0) is stable and production ready

As it is cross-platform, data can be transferred between little-endian and big-endian devices


Apache 2.0


Questions, suggestions, support: contact AT litereplica DOT io