Techniques for fin length variability control are provided. In one aspect, a method of patterning fins in a wafer includes: depositing a hardmask and a tone invert layer on the wafer; patterning trenches in the tone invert layer; forming inverse tone etch masks on the hardmask within the trenches, wherein the inverse tone etch masks include inner and outer inverse tone etch masks; forming a save mask with opposite ends thereof aligned with the outer inverse tone etch masks; using the save mask to selectively remove unmasked portions of the tone invert layer; removing the outer inverse tone etch masks, wherein the inner inverse tone etch masks that remain have a uniform length L; patterning the hardmask into individual fin hardmasks using the inner inverse tone etch masks; and patterning fins in the wafer using the fin hardmasks. A device having fins of a uniform length L is also provided.