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The photon transition form factors of $\pi$, $\eta$ and $\eta'$ are discussedin view of recent measurements. It is shown that the exact axial anomaly sumrule allows a precise comparison of all three form factors at high-$Q^2$independent of the different structures and distribution amplitudes of theparticipating pseudoscalar mesons. We conclude: (i) The $\pi\gamma$ form factorreported by Belle is in excellent agreement with the non-strange I=0 componentof the $\eta$ and $\eta'$ form factors obtained from the BaBar measurements.(ii) Within errors, the $\pi \gamma$ form factor from Belle is compatible withthe asymptotic pQCD behavior, similar to the $\eta$ and $\eta'$ form factorsfrom BaBar. Still, the best fits to the data sets of $\pi\gamma$, $\eta\gamma$,and $\eta'\gamma$ form factors favor a universal small logarithmic rise $Q^2F_{P\gamma}(Q^2)\sim \log(Q^2)$.

Universal behaviour of the $\gamma^*\gamma\to (\pi^0,\eta,\eta')$ transition form factors