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For any Boolean function f:{0,1}ⁿ → {0,1} with a complexity measure having value k ≪ n, is it possible to restrict the function f to Θ(k) variables while keeping the complexity preserved at Θ(k)? Instantiation of this question for the measure of circuit complexity of the Boolean function was shown to be related to circuit lower bounds (Buresh-Oppenheim and Santhanam, 2006). Variants of the above question were also shown to have connections to the log-rank conjecture in communication complexity (Hrubeš, 2024) and lower bounds in proof complexity (Razborov, 2016). In the context of communication and query complexity, this question was recently studied by Göös, Newman, Riazanov and Sokolov (2024). They showed, among other results, that query complexity cannot be condensed losslessly. In this work, we show that there exists a Boolean function f such that any restriction of f to O(ℳ(f)) variables has ℳ(⋅)-complexity at most Õ(ℳ(f)^{2/3}), where ℳ is one of block sensitivity (bs), fractional block sensitivity (fbs), certificate complexity (𝖢), deterministic query complexity (𝖣), zero-error randomized query complexity (𝖱₀), and AND (and OR)-decision tree query complexity. This improves upon the results of Göös, Newman, Riazanov, and Sokolov (2024) for 𝖣 and 𝖱₀, and in particular answers their open question about the condensation of block sensitivity. We complement the negative results on lossless condensation with positive results about lossy condensation. In particular, we show that for every Boolean function f there exists a restriction of f to O(ℳ(f)) variables such that its ℳ(⋅)-complexity is at least Ω(ℳ(f)^{1/2}), where ℳ ∈ {bs,fbs,𝖢,UC_{min},UC₁,UC,𝖣,deg̃,λ}. In addition, we show lossy condensation for randomized and quantum query complexity with a slightly smaller exponent.