<p>The expected precision at the FCC-ee on the product <InlineEquation ID="IEq1"> <EquationSource Format="MATHML"><math display="inline"> <mi>σ</mi> <mo>×</mo> <mi mathvariant="script">B</mi> <mfenced close=")" open="(" separators=",,,"> <mrow> <mi>H</mi> <mo>→</mo> <mi>b</mi> <mover accent="true"> <mi>b</mi> <mo stretchy="true">¯</mo> </mover> </mrow> <mrow> <mi>c</mi> <mover accent="true"> <mi>c</mi> <mo stretchy="true">¯</mo> </mover> </mrow> <mrow> <mi>s</mi> <mover accent="true"> <mi>s</mi> <mo stretchy="true">¯</mo> </mover> </mrow> <mi mathvariant="italic">gg</mi> </mfenced> </math></EquationSource> <EquationSource Format="TEX">\( \sigma \times \mathcal{B}\left(H\to b\overline{b},c\overline{c},s\overline{s}, gg\right) \)</EquationSource> </InlineEquation> of Higgs boson production cross sections times branching ratios of hadronic decays is presented. This study provides the first comprehensive determination of all major hadronic Higgs decay modes in a combined fit at future <i>e</i>⁺<i>e</i>^<i>−</i> colliders, using both Higgs-strahlung (<i>ZH</i>) and Vector boson fusion (<InlineEquation ID="IEq2"> <EquationSource Format="MATHML"><math display="inline"> <mi>ν</mi> <mover accent="true"> <mi>ν</mi> <mo stretchy="true">¯</mo> </mover> <mi>H</mi> </math></EquationSource> <EquationSource Format="TEX">\( \nu \overline{\nu}H \)</EquationSource> </InlineEquation>) production processes, with a full treatment of interference effects in the <InlineEquation ID="IEq3"> <EquationSource Format="MATHML"><math display="inline"> <mi>ν</mi> <mover accent="true"> <mi>ν</mi> <mo stretchy="true">¯</mo> </mover> <mi mathvariant="italic">jj</mi> </math></EquationSource> <EquationSource Format="TEX">\( \nu \overline{\nu} jj \)</EquationSource> </InlineEquation> final state. It assumes four identical IDEA detectors collecting <i>e</i>⁺<i>e</i>^<i>−</i> collisions at <InlineEquation ID="IEq4"> <EquationSource Format="MATHML"><math display="inline"> <msqrt> <mi>s</mi> </msqrt> <mo>=</mo> <mn>240</mn> </math></EquationSource> <EquationSource Format="TEX">\( \sqrt{s}=240 \)</EquationSource> </InlineEquation> and 365 GeV. The combination of all channels across both energies, with full covariance between production and decay modes, yields a production cross-section times branching-ratio precision at the percent to per-mil level for the dominant hadronic final states (<InlineEquation ID="IEq5"> <EquationSource Format="MATHML"><math display="inline"> <mi>b</mi> <mover accent="true"> <mi>b</mi> <mo stretchy="true">¯</mo> </mover> </math></EquationSource> <EquationSource Format="TEX">\( b\overline{b} \)</EquationSource> </InlineEquation>, <InlineEquation ID="IEq6"> <EquationSource Format="MATHML"><math display="inline"> <mi>c</mi> <mover accent="true"> <mi>c</mi> <mo stretchy="true">¯</mo> </mover> </math></EquationSource> <EquationSource Format="TEX">\( c\overline{c} \)</EquationSource> </InlineEquation>, <i>gg</i>). These results provide a comprehensive input to the determination of Higgs coupling projections at the FCC-ee, and they establish for the first time sensitivity to the rare decay <InlineEquation ID="IEq7"> <EquationSource Format="MATHML"><math display="inline"> <mi>H</mi> <mo>→</mo> <mi>s</mi> <mover accent="true"> <mi>s</mi> <mo stretchy="true">¯</mo> </mover> </math></EquationSource> <EquationSource Format="TEX">\( H\to s\overline{s} \)</EquationSource> </InlineEquation>, demonstrating that FCC-ee has the potential to provide evidence of the strange-quark Yukawa coupling.</p>