The F blues scale has 6 notes: F – A♭ – B♭ – C♭ – C – E♭. The blues scale is the minor pentatonic plus one note, the ♭5 or “blue note”. That note is a passing tone: slide or bend through it and the line sounds instantly bluesy. It works over all three chords of a 12-bar blues.
Compared with the F major scale it has ♭3 (A♭ instead of A), ♭5 (C♭ instead of C), ♭7 (E♭ instead of E).
The explorer above is set to F blues: the whole neck is mapped, and you can zoom into any of its 6 positions, change the labels to degrees or fingers, and hear it up, down and in patterns.