Eliminating a Quantifiably Unjust Application of the Law Act of 2021 or the EQUAL Act of 2021 This bill eliminates the federal sentencing disparity between drug offenses involving crack cocaine and powder cocaine. Currently, different threshold quantities of crack cocaine and powder cocaine (e.g., 28 grams of crack cocaine and 500 grams of powder cocaine) trigger the same statutory criminal penalties. This bill eliminates the lower quantity thresholds for crack cocaine offenses. Under the bill, the same threshold quantities of crack cocaine and powder cocaine trigger the same statutory criminal penalties. The change applies to future cases and cases pending on the date of enactment. With respect to past cases, the bill authorizes a sentencing court to impose a reduced sentence on a defendant who was convicted or sentenced for a specified crack cocaine offense before this bill's enactment. A defendant does not have to be present at the sentence reduction hearing. Finally, the bill prohibits the reduction of a sentence that was previously reduced.