The trending slogan reached a peak at 0200 (IST) today, hours after the bloody assault by two gunmen. Then, some 6,500 tweets were using the tag.
On Instagram, nearly 650,000 photos were shared with #JeSuisCharlie on them at 2130 IST yesterday. By 0630 IST today, the trend had declined to 52,000 shares.
An Instagram spokesman told AFP that yesterday's peak coincided with a Paris demonstration in homage to the victims killed that gathered at least 35,000 people.