This is honestly the biggest Byler proof we have. On the same day, Mike fights with both El and Will. During the Mileven fight, there is bright lighting and colours, sunny weather, funny, reactions, set in a public space, comedic with a happy aftermath. Contrastingly, the Byler fight is much more serious; dark lighting and colour, raining, private space, hurt expressions, and a very despondent aftermath. I think this really depicts how significant the fights with Mike affect El and Will, and shows how the writers/directors treat them both.

As a result, El laughs with Max as they ride home. El looks through magazines with teenage boys in them as they both have a fun time together. However, Will bikes home alone in the rain and travels to Castle Byers, his safe haven. His fight with Mike impacts him so much more than it does with El, as he completely destroys it while sobbing on the dirt. Parallels are very major in all types of film media and illustrate the difference between characters.

The fight before is just leading up to how contrasting Mike's reactions are to both fights. With El, he doesn't blame himself in the slightest, saying; "I don't understand what I did to deserve this." and refers to females as a 'species' and waits for El to call him. Max says that he will come back "begging for forgiveness". In spite of that, he actually does go begging for forgiveness, just not from El. He blames himself after Will's fight and bikes all the way across town in the rain to apologise.

During Robin's coming out to Steve, the song 'The First I love You' plays (note the lowercase letter in love). Similarly, during El and Mike's final kiss of the season (with Mike's eyes wide open by the way), the EXACT same song plays. In season 4, 'The First I Love You' plays when Joyce and Hopper finally kiss. For the entirety of season 4, Mike also struggled with saying 'I Love You' to El. I'll let you put two and two together.

This one is actually so crazily obvious I don't understand how people haven't realised this yet. These pictures alone literally provide you with enough evidence that Byler is going to be endgame. Also, these aren't the only photos of Byler paralleling canon couples, but these are the most clear ones. Byler is constantly paralleled with Lumax and Jancy, and El is always by herself. 

Mike and Will are always sitting/standing near each other in this season. Some may think this is the season with the LEAST amount of Byler evidence but you're actually wrong. This season is definitely the one with the MOST Byler evidence in the show. These aren't the only paralleling moments either, there are more, but they just aren't as obvious. Look closely next time you rewatch season 3 and you might find them!

In this scene at the hospital, Mike specifically wanted the Kit Kat, but it wasn't falling down. El helped him and made the chocolates fall, EXCEPT for the Kit Kat which is what Mike WANTED. This is a small symbol that El cannot give Mike want he wants. May I also add that the Kit Kat is situated between rainbow Skittles and Reeses Pieces (Will's favourite candy).

I'm going to refer to season 1 & 2 in this section. 'Crazy' is a term everybody links with love in this show. In season 1, a lady said to Nancy; "Only love makes you that crazy." In season 2, Mike and Will talk about going 'crazy together'. They understand what each other means. However, in season 3, Mike tries to have the same conversation with El by saying "You know what they say... it makes you crazy." She replies with "What makes you crazy?" They then keep talking and Mike realises she doesn't get it. She doesn't get it like Will does. This is because Mike is 'crazily in love' with Will, NOT El. El and Mike do not understand each other. This is also the beginning of Mike's inability to say he loves El. 

“It’s like a feeling, old people say it to each other." This is Mike projecting how he thinks couples should act, once again proving his heteronormative mindset. He wants to be straight so badly that he does what he thinks other couples (like Lucas and his dad) would do in this situation. He doesn't know how to act, so he is copying others.

Actually, I lied earlier. THIS is the biggest Byler proof we have. Eyewitness (2014) is about two boys, Philip and Lukas, who are in love in a small town. One of them doesn't want people to know. Mike is like Lukas because they are both coping with a great deal of internalised homophobia and self-hatred, which makes them lash out and deflect, originate from a cosy, traditional nuclear family and has a girlfriend as a beard. Will is like Philip because doesn't have a girlfriend, knows he is gay and originates from a working class family. These scenes on the left are exactly the same, even with the CAR in the background. Lukas says "I'm not gay like you!" which is very similar to Mike's; "It's not my fault you don't like girls." (Props to beepboop358).

I noticed this the very first time I watched the show. In this scene, Hopper's letter resembles Byler so much it's honestly a little scary. He says; “I've been stuck in one place. In a cave, you might say. A deep, dark cave.” This represents Mike stuck in the closet because of his internalised homophobia. Mike is starting to accept his feelings a little more. “But lately, I guess I've been feeling distant from you. Like you're pulling away from me or something.” Will and Mike are growing apart and also Will is moving away. "I miss playing board games every night." Mike misses playing DnD with Will.  “I don't want things to change.”  Mike is scared of change, he doesn't want to lose Will and for his life to become more complex. Also, after showing Mike when Hopper says this, it cuts straight to Will crying in the car, then back to Mike hugging his mom, causing these two to be centric of this scene which only proves this more.

Mileven and Byler are paralleled here. We have Mike and El who share a kiss at the end of the season as stated previously. Mike is starting to realise his feelings, causing him to not reciprocate their kiss, and El walking out while Mike seems visibly confused. Contrastingly, Mike and Will share a moment at the end of the season too, with Mike smiling big and bright after Will said he would never join another party. It is a very private and intimate moment between the two, after a season of despair, dejection and regret. Additionally, these two were the only one on one 'platonic' friendship pairing that had an ending scene together in this season.

Max is wearing a shirt that has rainbow sleeves and the rainbows are directly under Mike and Will who are sitting in the back of the car together. Everyone knows rainbows are associated with queer people and to put both Mike and Will underneath a rainbow is actually kinda crazy.

Caleb and Sadie (Lumax) have a photoshoot, Natalia and Charlie have a photoshoot (Jancy), Winona and David have a photoshoot (Jopper), and finally Noah and Finn have a photoshoot (Byler). Why didn't Millie and Finn (Mileven) have a photoshoot? More parallels.