About a year and a half ago, I made a post on the roll20 forums asking about ways to deal with lag in an exceptionally large campaign. Here's the tl;dr: 1. I have a huge campaign with 20+ DMs, 900+ maps, probably several thousand character sheets, both PCs and NPCs, as well as a bunch of handouts, tokens, rollable tables, and all the other things that go with a campaign that has gone on for over 4 years with an average of 5-8 sessions run per week. I fully understand that this is pushing the limits of what roll20 is meant to deal with. We know we're an edge case. 2. I was informed that "archiving" does not actually free up any memory as it is more of an organizational tool (a relic from pre-folder days) than an actual memory-saving tool (useful bit of info). Moreover, I was told by a roll20 mod that the primary issue would be the attributes from the journal sheets, as they are all loaded when a campaign is loaded and that maps (which as pages, are loaded dynamically), should not contribute to campaign lag . The reason I am here today is not to ask specifically for help, but to point out to others who are having similar issues that the advice I was given was incorrect, and that maps are the major contributor to campaign lag for people with larger campaigns . Side note: Now, in fairness to the mod in question, the roll20 built-in sheets for many systems are a massive bog of unnecessary journal attributes (see the first section of this post ), so if we had been using the built-in sheets, it's possible that would have been a major contributor; however, we used the "No sheet" format and just had about 15 standard attributes for our players to fill in (STR/CON/INT/etc. AC/Reflex/etc). The primary issue is that we were informed that maps should not contribute at all to campaign loading lag, which is demonstrably false. Some numbers! (We are still in the process of collecting data on this phenomenon, so more will be added.) Methods: Several complete copies of the game table were made (copying over Pages, Jukebox, Journals, etc but not Players or the Forums). Items were systematically deleted and the load times after deletion were recorded. Other copy campaigns were made, exlcuding either maps or journals but keeping other assets. All of the campaigns had WebRTC disabled (so no voice, video chat through roll20) to improve load time. Results: One of the DMs started by deleting all of the maps that were not his (eliminating 90+% of the maps in that campaign). The load time of the campaign went from about 75 seconds to about 14 seconds. This DM is to be commended in the effort he put in, as a mass-deletion tool for roll20 is conspicuously missing. (Vote for one here !) The content of the maps does not seem to have mattered. Deleting a "token storage" page that contained thousands of tokens had no noticeable effect on campaign load time. One caveat to point 2: Maps with dynamic lighting have longer individual load times when you click on them to open them up. This is not unexpected. A copied campaign that included all of the journals but none of the maps took approximately 12 seconds to load, compared to about 70 for the original campaign with all assets. A copied campaign that included all of the maps but none of the journals took approximately 60 seconds to load, compared to about 70 for the original campaign with all assets. Players with older equipment or slower internet connections (perhaps predictably) had much longer load times (up to several minutes) compared to those who had brand-new computers and Gigabit fiber connections. The lag in the original campaign was not limited exclusively to the initial campaign loading: macro prompts also often experienced delays between when they popped up and could be entered. Other noticeable victims of lag were rearranging attributes and abilities, rearranging sheets, time delay between pressing a macro and its result appearing in the chat window, and other basic roll20 functions. "Redboxing" was a fairly common occurrence, and the long load times made it challenging for players who had to reload. These issues were substantially reduced, usually to the point of unnoticeability, in the copy campaigns with reduced numbers of maps. Conclusions: Maps are, despite roll20 claims of being loaded dynamically, a major cause of campaign lag, and long-running campaigns that do not delete previous maps or "West Marches" or "LFR" style campaigns that accrue large numbers of players and maps are very vulnerable to lag from maps and other pages. While journals and sheets can contribute to this lag, they are, at least in the case of our campaign, not the major component of slow load times. I hope this post is useful to GMs in similar situations as well as potentially to roll20 devs who may not be aware of this issue. Good Hunting!