¶ Overview
For 90% of speedruns you should just go with the standard picks. Vitality is great but it's also a luxury you don't need usually. The stamina boosters and firebomb hellpods are pretty niche but they aren't worthless for speedrunning. The bottom tier boosters are useless for speedrunning so this page won't even cover them (for now).
The best time saver boosters for multiplayer? Either Hellpod Space Optimization or Muscle. For solo play Muscle is the must pick usually since you can take the resupply all to yourself at the start
¶ Hellpod Space Optimization (HSO)
What it does: spawn with full supplies
Worth taking for speedrun?: YES
Saves the team the call in time for supplies at the beginning and allows them to steer their hellpods at the start to split up more efficiently. A must pick for most runs except maybe in a very fast mission like blitz where you don't even care about most squad members having full supplies
¶ Muscle
What it does: increased movement speed through any terrain or effects that slow (uphill/downhill, sand, snow, acid slow, bushes)
Worth taking for speedrun?: YES
Most effective way to increase speed during the "walking simulator" portion of Helldivers 2. All biomes have elevation changes and various other environmental effects that slow players, and most big time sinks during a run are while walking over the natural terrain. Also the best way to reduce the slow effect some Terminids have, way more effective than motivational shocks (which only reduces slow by 0.7 seconds!)
¶ Experimental Infusion
What it does: 12.5% to 15% damage resistance and movement speed bonus while using a stim (buffs last 9.46 seconds). Fills screen with "drug effect" that zooms out FOV and upps contrast with yellow borders at edge of screen
Worth taking for speedrun?: Yes if there is room for it in a team's loadout and doesn't blind players
The only booster that directly impacts movement speed other than muscle. The buff lasts long enough for a significant time save even with just the 4 stims given at the start of a mission. Damage resistance is also nice for playing riskier and faster. Worth noting that the visual effect can make it very difficult to see on certain biomes at certain times of day (Vernen wells at night, Ustotu, Menkent etc.). Might be worth skipping if a team member complains they cant see anything with their computer setup and the booster
¶ Expert Extraction Pilot
What it does: 16% reduction in extraction timer (1:41 with no call in time, 2:30 with call in time)
Worth taking for speedrun?: Yes (even though it sucks) when map allows for quick clear of outposts/sides, very short missions where most of the run is extraction, and/or seeds with call in time modifier
Shitty booster, but it saves time in a speedrun in a lot of cases and is definitely worth considering or even a must pick for some missions (blitz). Its not even terrible for solo but it's still probably not worth bringing outside of very fast low diff runs.
¶ Niche Boosters
¶ Vitality
What it does: exact numbers complicated, but increases damage resistance including headshot damage reduction
Worth taking for speedrun?: Yes for missions with a lot of direct or risky engagements
Can let you take a faster route or kill enemies faster because you can take more hits from the enemy. Not always worth it if you're pretty much avoiding all enemies though in a very short mission like command bunkers or blitz
¶ Stamina
What it does: increased stamina bar, faster regen of stamina overall (around 30% longer sprint time from full bar in 50 armor, from 29 seconds w/o to 38 seconds w/ booster)(stamina recovery is 2 seconds faster with booster)
Worth taking for speedrun?: Maybe, if lots of sustained walking and other boosters not deemed important
Can be nice to have but not a must pick since stims or managing stamina through well timed sprints can often make the lower stamina bar and recovery a non issue, especially given that you can sprint for quite a while without having even recovered the full bar. Also worth noting that stamina recovers faster while crouching or prone so you can recover stamina while sneaking
¶ Firebomb Hellpods
What it does: any hellpods which come down (including resupply, sentry, support weapons, helldivers etc.) will ignite the surrounding area and enemies into flame
Worth taking for speedrun?: Yes but only for Eradicate.
Abosolute troll booster than is only good if your strategy involves burning through reinforces. For speedrunning Eradicate it can help you get a few more kills during a death loop of destruction. Otherwise avoid this mostly meme booster.
¶ Dead Sprint
What it does: allows for Helldivers to continue sprinting at the cost of health. Drains approximately 3.6% health (or ~1% with Vitality Enhancement) per second spent sprinting. Allows 25 seconds of continuous sprinting once out of stamina, and stops once health reaches 5%.
Worth taking for speedrun?: About as much as Stamina
Pretty much just a sidegrade to stamina booster, which isn't in the top tier of the speedrunning metagame. It offers more sprint time, in exchange for the risk of being at low health. Also fills your screen with an annoying blood effect that can make it difficult to see.
¶ Credits
Helldivers Wiki for some of the booster icons and information
https://helldivers.wiki.gg/wiki/Boosters