PNG SVG MORE
Signs & symbols
Glyph
Miscellany Web icons
Idea, light, lightbulb
Black
315x512
PNG ICO ICNS SVG MORE
Mixed
Free Misc Icon Set 2
power, bulb, lamp
512x512
Social Messaging & Productivity Mix Icons
light, Idea, bulb
506x512
Octicons
bulb, light
UI
Freecns Cumulus
WPZOOM Developer Icon Set
Idea, bulb, light
PNG MORE
Business & finance
Black ToolBar Icons
Idea, lamp, light
40x40
PNG ICO ICNS MORE
Desktop apps
16x16 Free Toolbar Icons
lamp, light, question
16x16