Font File Inspector & Glyph Coverage

What it is for

You have a font file called final2.ttf and want to know what it really is: its family and style names, its weight class, how many glyphs it has, and whether it can set the words you need, such as German umlauts, a euro sign or a Greek letter. The inspector reads that metadata from one TrueType or CFF OpenType file and checks every non-whitespace character of a sample text against the font's Unicode character map.

The font is uploaded to the server for this check. Lumina's Type Lab reads the same metadata locally in your browser if you would rather keep the file on your device. The inspector never installs or renders the font, and it does not search a font catalog or identify unknown lettering.

Worked example

We inspected DejaVuSerif-Bold.ttf with the sample text NORTHBOUND.

• Weight: 700, width class 5 (normal)
• Glyphs: 3506
• Units per em: 2048
• Unmapped sample characters: 0

The character mapping table lists the eight distinct letters N, O, R, T, H, B, U and D, each with its Unicode code point and a nonzero glyph index, so every letter of the sample is mapped. The license field starts with "Fonts are (c) Bitstream (see below). DejaVu changes are in public domain."

A second run with LiberationSans-Bold.ttf reported 2620 glyphs, the full name Liberation Sans Bold, version "Version 2.1.5", the PostScript name LiberationSans-Bold and a license record that begins "Licensed under the SIL Open Font License".

How to read the result

• Font metadata shows family, style, full name, format (TrueType or OpenType CFF), version and whether the file contains a variable-font table.
• Weight and width class come from the OS/2 table: 400 is regular, 700 is bold; width class 5 is normal, lower values are condensed and higher values are expanded.
• Units per em is the design grid. It matters when you compare metrics between fonts, not for everyday use.
• Character mapping (not shaping) has one row per distinct character. "Yes" means the character map points to a real glyph; "No" means the font would fall back to another font for that character.
• Unmapped sample characters sums up the misses. "Unknown" means the font has no Unicode character map this reader supports.
• The JSON download adds the copyright, license URL and the list of tables for documentation.

Tips and common mistakes

• Paste the exact text you plan to set, including punctuation and currency signs. Quotes, dashes and the euro sign are often the missing ones.
• Whitespace is ignored, and each character is listed once even if it repeats.
• A mapped character does not prove that a script shapes correctly. Arabic joining, Indic conjuncts, ligatures and emoji sequences need a real rendering test.
• Empty license fields do not mean the font is free to use. Check the vendor's license.
• WOFF, WOFF2 and font collections (TTC/OTC) are rejected. Use the original TTF or OTF file.
• For variable fonts, the reader reports the default instance's weight.

FAQ

Does the tool tell me which font is in an image?

No. It reads a font file you already have. To compare lettering in an image with candidate fonts, use Lumina's Type Lab.

Why is a character marked as not mapped when the text looks fine on my screen?

Your browser or editor probably substituted a fallback font for that character. The inspected file itself has no glyph for it.

Is my font file stored?

The file is uploaded for processing on the server. Use Type Lab if the font must stay on your device.

Can it check a variable font's axes?

It reports whether a variable-font table is present, but it does not list axes or instances.