This is part of the old website, it is no longer updated.

fontlint
A program for checking the validity of fonts

fontlint fontfile1 ...

fontlint checks a font for certain standard problems

It will notice:

• Any glyphs with intersecting (or self-intersecting) contours.
• Any contours drawn in the wrong orientation
• Any glyphs with a flipped reference
• Missing points at extrema.

For sfd fonts it will also notice:

• Any open contours (more an issue in sfd files than in released fonts)
• Adjacent points too far apart in a glyph
• Unknown glyph referenced in GSUB/GPOS/MATH

For PostScript fonts it will also notice:

• More points in a glyph than allowed by PostScript.
• Too many hints in a glyph.
• Invalid glyph name.
• Missing BlueValues entry in PostScript Private dictionary
• Odd number of elements in either the BlueValues or OtherBlues entries in the PostScript Private dictionary.
• Disordered elements in either the BlueValues or OtherBlues entries in the PostScript Private dictionary.
• Too many elements in either the BlueValues or OtherBlues entries in the PostScript Private dictionary.
• Elements too close in either the BlueValues or OtherBlues entries in the PostScript Private dictionary (must be at least 2*BlueFuzz+1 apart).
• Non-integral elements in either the BlueValues or OtherBlues entries in the PostScript Private dictionary.
• Alignment zone height in either the BlueValues or OtherBlues is too big for the BlueScale in the PostScript Private dictionary.
• Odd number of elements in either the FamilyBlues or FamilyOtherBlues entries in the PostScript Private dictionary.
• Disordered elements in either the FamilyBlues or FamilyOtherBlues entries in the PostScript Private dictionary.
• Too many elements in either the FamilyBlues or FamilyOtherBlues entries in the PostScript Private dictionary.
• Elements too close in either the FamilyBlues or FamilyOtherBlues entries in the PostScript Private dictionary (must be at least 2*BlueFuzz+1 apart).
• Non-integral elements in either the FamilyBlues or FamilyOtherBlues entries in the PostScript Private dictionary.
• Alignment zone height in either the FamilyBlues or FamilyOtherBlues is too big for the BlueScale in the PostScript Private dictionary.
• Bad BlueFuzz entry in PostScript Private dictionary.
• Bad BlueScale entry in PostScript Private dictionary.
• Bad StdHW entry in PostScript Private dictionary.
• Bad StdVW entry in PostScript Private dictionary.
• Bad StemSnapH entry in PostScript Private dictionary.
• Bad StemSnapV entry in PostScript Private dictionary.
• StemSnapH does not contain StdHW value in PostScript Private dictionary.
• StemSnapV does not contain StdVW value in PostScript Private dictionary.
• Bad BlueShift entry in PostScript Private dictionary.
• Bad 'CFF ' table.

For TrueType fonts it will also notice:

• More points in a glyph than specified in 'maxp'
• More paths in a glyph than specified in 'maxp'
• More points in a composite glyph than specified in 'maxp'
• More paths in a composite glyph than specified in 'maxp'
• Instructions longer than allowed in 'maxp'
• More references in a glyph than specified in 'maxp'
• References nested more deeply than specified in 'maxp'
• Bad 'glyf' or 'loca' table

In any sfnt (True or OpenType font):

• Bad sfnt table header, bad file/table checksums, overlapping tables, standard tables with incorrect lengths, etc.
• Bad PostScript fontname entry in the 'name' table
• Bad 'hhea', 'hmtx', 'vhea' or 'vmtx' table
• Bad 'cmap' table
• Bad 'EBDT', 'bdat', 'EBLC' or 'bloc' (embedded bitmap) table
• Bad Apple GX advanced typography table
• Bad OpenType advanced typography table
• Bad version number in OS/2 table (must be >0, and must be >1 for OT-CFF fonts)

See Also

FontForge