Four independently reduced JWST transmission spectra of K2-18 b. NIRISS SOSS and NIRSpec G395H data sets reduced using the FIREFLy pipeline (green error bars; Z. Rustamkulov et al. 2022, 2023; Liu & Wang et al. 2025, in preparation; Wang et al. 2025, in preparation) are compared with the same data reduced with the exoTEDRF pipeline (blue error bars; A. D. Feinstein et al. 2023; M. Radica et al. 2023; M. Radica 2024) and two NIRSpec G395H reductions using the Eureka! pipeline (error bars with gray (B)/white (A) central points; T. Bell et al. 2022). NIRISS data are shown at R ≈ 25, and NIRSpec data are shown at R ≈ 100. The four reductions demonstrate broad agreement.