Last modified: Friday, October 17, 2025

Default C Language Standard in gcc

gcc, C language

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The C compiler gcc in GCC (The GNU Compiler Collection)[External Site] supports several C language standards. If you do not specify a C language standard with the gcc command line option -std=, the default C language standards are shown in the table below.

If you want to use a newer (or older) C language standard, you must specify it explicitly by the command line option.

Correspondence between gcc versions and default C language standards
gcc versionrelease datedefault C language standard
2.95.32001-03-16gnu89 (ISO9899:1990+GNU extensions)
3.0.42002-02-20gnu89 (C89+GNU extensions)
3.1.12002-07-25gnu89 (C89+GNU extensions)
3.2.32003-04-22gnu89 (C89+GNU extensions)
3.3.62005-05-03gnu89 (C90+GNU extensions)
3.4.62006-03-06gnu89 (C90+GNU extensions)
4.0.42007-01-31gnu89 (C90+GNU extensions)
4.1.22007-02-13gnu89 (C90+GNU extensions)
4.2.42008-05-19gnu89 (C90+GNU dialect)
4.3.62011-06-27gnu89 (C90+GNU dialect)
4.4.72012-03-13gnu89 (C90+GNU dialect)
4.5.42012-07-02gnu90 (C90+GNU dialect)
4.6.42013-04-12gnu90 (C90+GNU dialect)
4.7.42014-06-12gnu90 (C90+GNU dialect)
4.8.52015-06-23gnu90 (C90+GNU dialect)
4.9.42016-08-03gnu90 (C90+GNU dialect)
5.52017-10-10gnu11 (C11+GNU dialect)
6.52018-10-26gnu11 (C11+GNU dialect)
7.52019-11-14gnu11 (C11+GNU dialect)
8.52021-05-14gnu17 (C17+GNU dialect)
9.52022-05-27gnu17 (C17+GNU dialect)
10.52023-07-07gnu17 (C17+GNU dialect)
11.52024-07-19gnu17 (C17+GNU dialect)
12.42024-06-20gnu17 (C17+GNU dialect)
13.42025-06-05gnu17 (C17+GNU dialect)
14.32025-05-23gnu17 (C17+GNU dialect)
15.22025-08-08gnu23 (C23+GNU dialect)

How to specify C language standards

For gcc 2.95.3 and earlier, specify with the -fstd= option. For gcc-3 and later, specify with the -std= option.

Related Links

Atsushi NUNOME @ Computer System Laboratory at Kyoto Institute of Technology (nunome@kit.ac.jp)