Making the free tier more restrictive for current users is probably a bad idea. The generally accepted thing to do is grandfather free users in. How important

Making the free tier more restrictive for current users is probably a bad idea. The generally accepted thing to do is grandfather free users in. How important are free users to your app? Is it a network-effect, where those free users make your service better? If not, you may toy with removing free entirely. You'll remove a lot of support time/costs, and only keep around paying customers. Free plans are effectively a type of marketing. The cost to support those free users adds to the acquisition cost per user, which means you need a higher lifetime value from each paying user. As an alternative to slashing Free, you could make your Paid tiers better. And aggressively try to convert free users. Send drip campaigns, show them screencasts about your Paid tiers, etc etc. Free users can be converted. You need to find out why they are staying free. Price may be the reason, or maybe not. Do some customer outreach to both free and paid and find out why the two populations are in their current tier.