Approximation properties of quasi-projection operators $$Q_j(f,\varphi , \widetilde{\varphi })$$
Q
j
(
f
,
φ
,
φ
~
)
are studied. These operators are associated with a function $$\varphi $$
φ
satisfying the Strang–Fix conditions and a tempered distribution $$\widetilde{\varphi }$$
φ
~
such that compatibility conditions with $$\varphi $$
φ
hold. Error estimates in the uniform norm are obtained for a wide class of quasi-projection operators defined on the space of uniformly continuous functions and on the anisotropic Besov-type spaces. Under additional assumptions on $$\varphi $$
φ
and $$\widetilde{\varphi }$$
φ
~
, two-sided estimates in terms of realizations of the K-functional are also established.