OpenSans includes complete Latin Basic, Latin-1 Supplement, Latin Extended-A, and Cyrillic character sets, plus Greek and Coptic, Cyrillic supplementary, and Latin Extended Additional characters to support many languages. 

Its coverage of other character sets is limited, with just the superscripts for 0-9, five Currency Symbols, seven Letterlike Symbols, four Number forms, twelve Mathematical Operators, one geometric shape, and no Miscellaneous Symbols or Dingbats. It has five Alphabetic Presentation forms: ff fi, fl, ffi, ffl.

The Apache license allows others to enhance or modify the font, provided that they document the changes in the font and distribute their own version under the same license conditions.

Version 1.2 (31/1/2016 )
- Embedding flag set to "Installable" so that it will be used by Internet Explorer when embedded on Web Pages. 
- Added the Latin Extended Aditional glyphs needed for Romanised Pali and Sanskrit
- Saved all ten weights as a single font family: Open Sans

Version 1.3 (2/2/2016 )
- Added General Punctuation for hyphen, non-breaking hyphen, figure dash, interrobang, triangular bullet, leftwards and rightwards bullets 
- Added subscripts for scientific inferiors and baseline denominators for fractions
- Added Currency Symbols for Drachma, Ruble, and Georgian Lari
- Added Letterlike Symbols Phonographic copyright, Information, Telephone and Fax for Stylistic Alternates
- Added Number Forms for all fractions
- Added some Miscellaneous Technical
- Added a complete  sets of Arrows, Geometric Shapes, Miscellaneous Symbols, and Dingbats
- Added an Apple Logo to the Private use Area
- Add Miscellaneous Symbols and Pictograms for Sunrise and Moon Phases for Stylistic Alternates
- Added OpenType Features for Fractions, Superscripts, Subscripts, Scientific Inferirors, Stylistic Alternates, and Ornaments
- Replaced previous kerning with class-based kerning 

Version 1.40  (3/2/2016 )
- Added Custom Naming Fields
- Added Ordinals Feature

Version 1.50  (4/2/2016 )
- Improved Stylistic Set 3
- Reduced size of web versions

Version 1.60  (5/2/2016 )
- Fixed metrics to prevent cropping 
- Added Alternate Annotation Forms (Enclosed numerics 1-20)

Version 1.70  (8/2/2016 )
- Added Discretionary Ligatures
- Added kerning pairs for ligature glyphs

Version 1.71  (9/2/2016 )
- Harmonised spacing and weight of Maths Symbols
- Deleted duplicate glyphs
- Mapped OldStyle Figures
- Mapped stacking diacritics