  LSST will supply up to $10^6$ supernovae (SNe) to constrain dark energy
through the distance-redshift ($D_L$-$z$) test. Obtaining spectroscopic SN
redshifts (spec-$z$s) is unfeasible; alternatives are suboptimal and may be
biased. We propose a powerful multi-tracer generalization of the
Alcock-Paczynski test that pairs redshift-free distance tracers and an
overlapping galaxy redshift survey. Cross-correlating $5\times 10^4$
redshift-free SNe with DESI or Euclid outperforms the classical $D_L$-$z$ test
with spec-$z$s for all SN. Our method also applies to gravitational wave sirens
or any redshift-free distance tracer.
