* Corrosive Haze followed by Slithereen Crush takes advantage of Alchemist's main weakness, being physical damage before he has the change to improve his surviability with items.
* Bash of the Deep will deal lots of damage during the laning phase.
Additional:
* Alchemist has a low starting armor and a low agility growth, which translates to a low armor growth . And since it is very uncommon for Alchemist to get straight to Assault Cuirass, or Shiva's Guard, Corrosive Haze makes him too vulnerable to physical damage, even with the hp regeneration of Chemical Rage

* Weaver relies on Shukuchi to escape and kite enemy heroes. Slardar's Corrosive Haze lowers armor and reveals Weaver, who is already a very frail target.
* Weaver usually builds Linken's Sphere, Corrosive Haze can be used to "pop" the spell block of Linken's Sphere, additionally the level 25 undispellable talent will prevent Weaver from removing Corrosive Haze with Time Lapse, allowing allied heroes to use their abilities on Weaver.
Additional:
* Corrosive Haze lowers armor and reveals Weaver during Shukuchi, who is already a frail target. In addition, Weaver usually builds Linken's Sphere, and Corrosive Haze can be used to "pop" the spell block. His level 25 talent can also make Corrosive Haze undispellable by Time Lapse, which puts Weaver in an even worse situation.
* Guardian Sprint can dodge Weaver's bugs with the movement speed bonus.

* Skywrath Mage can easily harass Alchemist in the laning phase with multiple Arcane Bolts. Additionally, if Alchemist is in the process of throwing an Unstable Concoction, and has no way to dispel Ancient Seal, the self stun becomes an easy set up for Mystic Flare.
* Caution, however, as a decently farmed Alchemist with {Item ID:Radiance} and {Item ID:Manta Style} can easily send illusions to harass and force Skywrath Mage out.

* Even though Linken's Sphere will block your silence, you can cast Arcane Bolt to break it or wait until someone on your team breaks it. In addition, Linken's Sphere builders are usually squishy targets vulnerable to silences: Weaver, Queen of Pain, Morphling, Clinkz, etc. Don't forget that Ancient Seal also increases the magical damage these enemies take, along with silencing them.

Additional:
* Arcane Bolt has a long range and a low cooldown, and is a great spell to waste Linken's Sphere. It also serves as an effective spell to harass Weaver with.
* Ancient Seal prevents Weaver from using Shukuchi or Time Lapse.

* Spiked Carapace allows Nyx to get an easy long-duration stun on Weaver once he uses Shukuchi, and then he can follow up with Impale.
* Vendetta works as a great setup for both Impale and Spiked Carapace and can deal decent damage to Weaver. Additionally he can neutralize The Swarm beetles due to his invisibility duration.

* The long silence of Crippling Fear at night prevents Weaver from using his Shukuchi or Time Lapse.
* With Dark Ascension and Gem of True Sight, Night Stalker can easily find and probably kill Weaver.
* Hunter In the Night's attack speed bonus removes The Swarm's beetles very quickly.

* Shadow Shaman's many disables can lock down Weaver. Even with Linken's Sphere, Weaver might not be able to escape should Shadow Shaman uses Shackles quickly enough following Hex.
* Mass Serpent Ward can make short work of Weaver once he is locked down.

* Shukuchi will trigger extra damage from Rupture.
* Shukuchi's invisibility is detected by Thirst.
* Time Lapse cannot dispel Rupture, preventing Weaver from escaping ganks.
Additional:
* Rupture is particularly crippling against Weaver, who relies on high movement speed from Shukuchi to fight and escape, and it cannot be dispelled by Time Lapse.
* Thirst detects Weaver through Shukuchi whenever his health is low.
* Blood Rite combined with Rupture forces Weaver to either take damage from the latter, or to get silenced for a long duration.

* Fireblast with Multicast can prevent Weaver from escaping with Shukuchi.
* However, the slow from Ignite is generally useless against Shukuchi haste effect or dispelled by Time Lapse.

* Quas-Exort Invoker can win the mid lane easily against Alchemist because Quas regeneration will nullify Acid Spray's damage over time and Exort damage bonus will allow Invoker to out last hit Alchemist.

* Although Weaver can potentially Time Lapse out of any burst, Weaver has a fragile health pool, and Lion's disables can kill him before.
* Weaver is very mana dependent and has a rather small mana pool in the beginning of the game. Mana Drain can deplete him of mana and lessen his early game presence.
* Earth Spike can be point targeted and hits through Shukuchi to make him vulnerable.
* Linken's Sphere is easily broken by targeted spells with low cooldown.

* Ball Lightning allows Storm Spirit to close the gap between him and Weaver in no time. Once locked down with certain items, Weaver is extremely fragile to Storm Spirit and his teammates.

* Shadow Dance allows Slark to not be targeted by Unstable Concoction, making Alchemist stun himself and making himself vulnerable to the enemy.
* Dark Pact also allows him to just purge off the stun if timed correctly.
* Essence Shift will steal stats over long durations at a time should Alchemist lack the damage to kill Slark.

* Smoke Cloud prevents Shukuchi and Time Lapse, leaving Weaver helpless against Riki.
* The Swarm is ineffective against Riki because invisibility instantly removes the beetles.

* Shukuchi cannot help Weaver escape from Arena of Blood, so with vision, Weaver is an easy kill.
* Time Lapse will also not save Weaver in a large amount of situations inside Arena of Blood, especially if he's pinned to the walls with Spear of Mars.
* The Swarm and Geminate Attack is not very useful against a hero that can tank 70% of his main damage source.

* Berserker's Call is one of the best ways to lock down Weaver before he has a chance to use Time Lapse. It can also catch Weaver in Shukuchi.
* Weaver's high attack speed, along with high attack damage from Geminate Attack, triggers Counter Helix continuously and the output damage would be returned by Blade Mail.
Additional:
* Berserker's Call is one of the best ways to lock down Weaver before he has a chance to use Time Lapse. It can also catch Weaver in Shukuchi.
* Due to his fast attack speed from Geminate Attack and items that give attack speed, Counter Helix will activate a lot, and the damage would be returned by Blade Mail, which hurts Weaver far more than it hurts Axe.
* Culling Blade can finish off Weaver's low health pool before he escapes with Shukuchi and Time Lapse.
* Battle Hunger is a good tool to pop Weaver's Linken's Sphere due to its low cooldown.

* A well-timed Gust will prevent Weaver from escaping, and a silenced Weaver usually dies very quickly.
* Precision Aura easily removes The Swarm beetles or counteracted by Shadow Blade/Silver Edge.
Additional:
* A well-timed Gust followed by Frost Arrows will prevent Weaver from escaping with Shukuchi. A Weaver silenced for more than 3 seconds usually dies very quickly.
* Due to her high attack speed, Drow Ranger can easily kill The Swarm beetles.

* Duel's long duration prevents Weaver from activating Time Lapse or escaping with Shukuchi.

* Phantom's Embrace and Soulbind prevent Weaver from using Shukuchi or Time Lapse to escape.
* Ink Swell discourages Weaver from moving through and damaging allies with Shukuchi.

* Ember's magic damage build is able to burst down Alchemist due to his low strength gain and Alchemist's normal item pick up.

* Tidebringer will deal lots of damage to Alchemist before he builds physical survivability items.
* Torrent and X Marks the Spot can control Alchemist at all stages of the game before he has Black King Bar.
* Ghostship's rum buff will greatly reduce the Alchemist's damage output in teamfights including his Radiance.

* Time Dilation while Shukuchi and Geminate Attack are on cooldown will make these abilities unusable for a long time, reducing Weaver's escape potential.
* Chronosphere will reveal Weaver during Shukuchi.
Additional:
* The wide range of Chronosphere makes it difficult for Weaver to avoid it with Shukuchi and, once caught, his low survivability makes him an easy kill.
* With no significant source of burst damage, it is easy for Void to survive combat with Weaver using Time Walk.
* Time Dilation will prevent Weaver from using Shukuchi or force him to use Time Lapse to dispel the debuff and re-engage.

* Visage can quickly kill heroes with low to medium base armor and no innate escape mechanism. Examples include Alchemist, Crystal Maiden and Zeus.

* Low-health, normally mobile carries with a lot of damage are vulnerable to Bane's nukes and disables: Anti-Mage, Clinkz, Drow Ranger, Faceless Void, Gyrocopter, Juggernaut, Luna, Meepo, Mirana, Monkey King, Morphling, Phantom Assassin, Phantom Lancer, Riki, Shadow Fiend, Slark, Sniper, Terrorblade, Troll Warlord, Weaver.

* Clinkz can use Burning Army in teamfights which will cause a problem for Alchemist.

* Pugna's Decrepify makes sure that either Alchemist is unable to hit anyone while also being slowed and susceptible to magical damage, or can protect an ally from physical attacks. Besides, Pugna can push early on, when Alchemist is not strong enough to repel it, so by the time Alchemist comes online, he might be forced to sit in base.

* Melee heroes that get kited easily have hard times dealing with Puck without any lockdowns, as Puck is one of the most mobile heroes. Heroes like Sven, Lifestealer, Ursa and Alchemist may have problems to get to Puck without proper initiation items. They also lack reliable lockdowns, as their disables are easily avoidable for Puck, or are just a soft disable.

* In general, melee heroes without blink mechanisms or spell immunity will have a hard time positioning against Pit of Malice: Sven, Tiny, Wraith King, Dragon Knight, Meepo, Doom, Bounty Hunter, Dark Seer, Undying, Alchemist, Legion Commander.

* Frostbite will reveal invisible heroes for its duration, making it a good tool against any such hero (Riki, Bounty Hunter, Weaver, or Clinkz for example), or as a soft counter to Shadow Blade, if it is used first. This can be an amazing tool to ensure that Dust of Appearance is used on the unit in question, and not wasted in not catching anything.

* Heroes who rely on skills to become a heavy hitter in a certain amount of time can waste their timing because of a lucky Lucky Shot's disarm: Terrorblade, Sven, Clinkz, Windranger, Alchemist, Dragon Knight, Legion Commander

* Silences and other types of lockdown that prevent Weaver from using his spells: Silencer, Riki, Lion, Legion Commander, Shadow Shaman, Bane.

* Earthshaker's many stuns can lock down slippery heroes like Slark in his Shadow Dance and Weaver in his Shukuchi.

* Techies is very good against roaming supports and gankers such as Bounty Hunter, Riki, Weaver, Earthshaker, Nyx Assassin, etc. that are constantly moving around the map.

* Heroes that avoid damage by coming in and out of invisibility in teamfights such as Weaver, Templar Assassin, and Riki will be easy for Zeus to reveal with Lightning Bolt and Thundergod's Wrath, but these heroes usually have other ways to avoid his damage or kill him, so he is not a perfect counter alone.

Additional:
* Arc Lightning has a low cooldown can used to pop his Linken's Sphere.
* Lightning Bolt or (Nimbus upgraded from Aghanim's Scepter) detects Weaver during Shukuchi, preventing his ganks.
* Thundergod's Wrath can kill Weaver quickly before he can cast his Time Lapse at low health.

* Heroes with high mobility can be prevented from using it to their advantage with Earthbind, even if they pack a dangerous arsenal: Earth Spirit, Ember Spirit, Storm Spirit, Nature's Prophet, Phantom Assassin, Riki, Anti-Mage, Weaver.
* See items and abilities disabled by roots

* Sprout is good for trapping melee carries with no escape abilities: Sven, Ursa, Alchemist, Lifestealer etc.

* Sprout with True Sight items like (Necronomicon 3, Sentry Ward or a Gem of True Sight) make it possible to trap Weaver in lane, unless he buys Quelling Blade or until he uses Time Lapse.
* The Swarm beetles can be destroyed with Nature's Prophet's treants or Necronomicon.
* Nature's Prophet allows Purge on Necronomicon 3 to be used to pop his spell block following up with items like (Nullifier, Scythe of Vyse or Bloodthorn) or Wrath of Nature.

* Heroes that lack burst damage will have a difficult time taking down Monkey King, and fare badly against Jingu Mastery: Legion Commander, Lifestealer, Weaver, Wraith King

* Alchemist has very bad armor and does not build armor items for the large majority of his build, so Jingu Mastery and Wukong's Command can be very deadly.
* Desolator, Sange and Yasha or Diffusal Blade can all be purchased to increase your damage against Alchemist or just to keep your movement speed high enough to match him while Chemical Rage is active.
* Monkey King is an agility hero and scales with armor, so Acid Spray loses it's effectiveness later in the game.

* Reaper's Scythe can kill Alchemist before Chemical Rage has the time to heal him.
* Ghost Shroud can prevent Alchemist from attacking Necrophos, as well as make him immune to Acid Spray and Unstable Concoction damage.
* Heartstopper Aura will do damage as long as Necrophos is alive based on health percentage, which is a problem for a strength hero such as Alchemist.

* Alchemist is a well-known Radiance carrier among other auras your illusions will benefit from. They also get the extra move speed and reduced base attack time from his Chemical Rage, and it's even better if you can catch him as his own rage is about to expire.
* Disruption will buy enough time for all allies to retreat when Alchemist starts to activate Unstable Concoction.

* Untouchable greatly reduces Chemical Rage's attack speed advantage.