Facebook’s Gross National Happiness (FGNH) indexes the positive and negative words used in the millions of status updates submitted daily by Facebook users. FGNH has face validity: it shows a weekly cycle and increases on national holidays. Also, happier individuals use more positive words and fewer negative words in their status updates (Kramer 2010). We examined the validity of FGNH in measuring mood and well-being by comparing it with scores on Diener’s Satisfaction with Life Scale (SWLS), administered to an average of 34 Facebook users every day for a year, then aggregated by day, week, month, quarter and half year. FGNH and SWLS were not significantly correlated, with a negative correlation coefficient. Also, aggregated SWLS scores showed a positive relationship with numbers of negative words in status updates. We conclude that FGNH is a valid measure for neither mood nor well-being; however, it may play a role in mood regulation. This challenges the assumption that linguistic analysis of internet messages is related to underlying psychological states.