["Applied Psychology: Health and Well-Being, Volume 18, Issue 4, August 2026. ", "\nAbstract\nThis randomized controlled trial compared 4‐week self‐guided self‐compassion meditation (SCM) and mindfulness meditation (MM) apps among workers in two active arms (n = 201); analyses included intervention initiators with session‐level data (SCM n = 86; MM n = 85). Primary daily outcomes were pre‐session levels and immediate pre–post changes in HR, heart rate variability by RMSSD, and subjective relaxation; secondary weekly outcomes were PANAS and Affect Grid scores. Repeated‐measures ANOVA and linear mixed models examined time and group effects. Daily models showed increased pre–post RMSSD differences and pre‐session HR across days in SCM, stronger pre–post HR reduction and increased pre‐session HR in MM, and reduced pre–post relaxation differences in both groups, with no group × day interactions. Weekly LMM analyses suggested reduced negative affect in SCM; however, SCM and MM showed broadly comparable effects, with no significant group × time interactions across daily and weekly outcomes. These findings support the value of short‐term trajectories and physiological markers and warrant longer follow‐up.\n"]