Oxygen O2 black outline icon
Large circle beside a bold numeral two with three small bubbles, forming the O2 formula
About the Oxygen O2 black outline icon
The chemical formula for oxygen is drawn as a large open circle standing in for the letter O beside a bold numeral two, with three small bubbles of different sizes floating around it. Useful for medical and respiratory apps, oxygen tank and cylinder labeling, air quality dashboards, chemistry lesson slides, and diving or altitude fitness content.
The main ring dominates the frame while the numeral sits low and heavy on the right, and the scattered bubbles fill the corners to balance the layout. It pairs with molecule, lungs and air purifier icons. Keep it at 32 px so the smallest bubbles survive.
This is the black outline version of the oxygen o2 icon: even, monoline strokes that stay crisp at small sizes and suit clean, minimal interfaces, wireframes and light backgrounds.
It downloads free as an SVG vector or transparent PNG in seven sizes, and the free online editor lets you recolor it, apply gold, silver, neon and gradient styles, add animation, or convert it to EPS, PDF and DXF.
Free for personal and commercial use with attribution.
