Here is a collection 1000 free line icons that mix well on minimal designs. Outline Icons come with different formats like PSD, AI, EPS, SVG, Icon Fonts, and more. These line icon packs are available for personal as well as commercial design projects.
Rivolicons
Rivolicons pack includes 132 icons in various formats including SVG, PDF, and icon font.
Buddha Line Icons Set Vol.1
These icons are in vector quality and can be used for app development and web design.
Free Line Icon Set
Vector Line Icons
Here are vector-based icons that come in PDF, SVG, EPS, PNG, and icon font.
Free Line Icons
This next pack comes with 210 icons in PSD, PNG, SVG, and Icon Font.
Ingenicons
Freeline Icons
Pixelicons
This pack gives away 100 icons in AI, EPS, SVG, CSH, PDF, Android, and iOS.
Bubbles Iconset
Tomicons
Feather Icons
Feather icons is a collection of 130 free simple icons that are available in web font, PSD and SVG formats.
Simple Outline Icons
These icons come in varied formats such as PNG (33px, 60px, & 90px), PDF, SVG, ESP, and PSD.
Also check out: Emoticons and Smiley Icons Set