Sort Kerning Pairs by Value in FontForge

Managing kerning values in FontForge is essential for spotting extreme overlaps, unwanted loose spacing, and typographical inconsistencies. This guide explains how to access your font's kerning lookup data and sort kerning pairs by their numerical value using FontForge's built-in table tools.

Step 1: Open the Font Info Window

  1. Open your project in FontForge.
  2. Go to the top menu and select Element > Font Info, or press Ctrl + Shift + F (Cmd + Shift + F on macOS).

Step 2: Navigate to Kerning Lookups

  1. In the sidebar on the left side of the Font Info dialog, click on Lookups.
  2. Select the GPOS (Glyph Positioning) tab located along the top of the Lookups panel.
  3. Locate your kerning feature in the list. It is typically named 'kern' Horizontal Kerning or listed under a pair positioning lookup.
  4. Click the small arrow or plus sign next to the lookup to expand it and reveal its subtables.

Step 3: Open the Kerning Subtable

  1. Click on the kerning subtable you wish to inspect to highlight it.
  2. Click the Edit Data button on the right-hand side of the window (or double-click the subtable name).

Step 4: Sort Kerning Pairs by Value

  1. If your subtable contains individual pairs, navigate to the Kerning Pairs tab in the subtable editor.
  2. You will see a list with columns displaying the first glyph, the second glyph, and the numeric kerning offset (often labeled Offset or Amount).
  3. Click the column header corresponding to the kerning value/offset.
  4. The entire list will sort numerically. Click the column header a second time to toggle between ascending order (the most negative values, indicating tight overlaps) and descending order (positive values, indicating added space).

Using the Metrics View for Visual Inspection

If you need to visually review your sorted pairs directly in the workspace:

  1. Close the Font Info dialog after noting the pairs you want to adjust.
  2. Select Metrics > Open Metrics Window from the main menu.
  3. Enter the specific glyph pairs into the text area to view and manually adjust the spacing values with immediate visual feedback.