aaaaaaaauuuuuugggggggghhhhhhhhh

Simple go if it’s to hard for you then go into your files delete the data start over and do a neutral route or pacifist but still give it an honest try before

But if your so determined just search up sans fight simulator for practice

Don't die

overcome your skill issue

Tip: if you're dying, get good at the game!

Tip: reset

Right.
Get a piece of paper and a pen or remember this comment bc these are his attacks (in order!):
First Wave
This is the first wave of (13) attacks Sans will do. Key: ~ = middle, < = left, > = right, ^ = up, and v = down.

1. "Strongest Attack" Down throw, Maneuver through wavy bone path, Gaster Blaster Pattern: (~, ^, ~, ^).
2. Jump through slots (all low down)
3. Blue - White jumps (blue = stay still and white = jump over)
4. Jump through slots (assorted heights; always random)
5. First Platforms (3rd platform has bones above; bone comes in at very end)
6. Second platforms ( pretty straightforward; last platform: jump above tall bone and stay still)
7. Left and Right bone platforms - stay at bottom, move left, jump up, right, and repeat.
8. 3 Pillar slots (hard - slide through medium sized slots)
9. Gaster Blaster Platforms (ALWAYS RANDOM - Very hard)
10. 3 Pillar slots (very hard - slide through small sized slots)
11. Jump through slots (all low; faster)
12. Slot-to-slot (stay in one, jump up, left and repeat until done)
13. Jump through slots (assorted heights; random; faster)

Sans should now tell you that you can still be a good person and allow you to spare, but DO NOT SPARE! You will be instantly killed!
Second Wave
These attacks take place after Sans says, "welp, it was worth a shot".
(list resumes after 13.)

14. On-and-off - His attacks will change abruptly after a few seconds and will change about 4-5 times. (always random)

*A bone should be on the left side of menu - CAN DEAL DAMAGE WHILE SELECTING SANS' NAME - BE CAREFUL*

You should be changed to a red heart now.

15. Gaster Blaster Flurry - rapidly firing gaster blasters will fire acros the board - Sea Tea recommended
16.On-and-off - abruptly changing attacks (includes wavy bone path; harder this time)

*Sans should now be putting bones across the FIGHT/ACT/ITEM/MERCY buttons; you can take damage white trying to eat healing items*

17. Slamming - He will slam you around the box; jump shortly after getting hit against the wall to avoid bones.
Pattern: (<, >, ^, v, >, ^, >, v, ^)

18. Slamming
Pattern: (>, <, >, >, ^, ^, v, >, <)

19. Gaster Blaster Flurry (Harder; wider beams; Sea Tea recommended)
20. Bones on either side of screen will go up (right) Down (left); MOVE IN COUNTERCLOCKWISE CIRCLES TO AVOID!
21. On-and-off - EXTREME! (3x+ Wavy path)
22. Slamming (bones are taller this time)
23. Slamming
Pattern: (>, v, v, <), then you will be taken straight to attack 20's pattern.

(continuing bc imgflip made my comment shorter)
Straitht to EXTREMELY FAST WAVY PATH, then move up and down to avoid pillars. Next, move straight to the middle to avoid a narrowing path, and last avoid the slam on the far wall.
24. On-and-off ; EXTREMELY HARD!
Pattern: (top, bottom, right, and left indicate places bones come from) (top and bottom, top and left, bottom and right, left)

Third Wave
This is the final wave consisting of 2 attacks.

25. Gaster Blaster Spiral - HARDEST ATTACK! - Move counter-clockwise in a paced manner, avoiding the center for about 10 seconds. THIS IS THE FINAL ATTACK!

26. Sans will slam you randomly against the walls. You cannot die. You will end with 1 health.

Congratulations, you are done! Wait for him to fall asleep and move the box over the FIGHT icon to attack him and thus end the battle.

Good luck with beating sans and I hope this helped!
If it doesn't then you should write down his moves in your own way that you'll remember, the key to beating most Undertale bosses is memeory

thank you 👌💯💯

No problem

If you beat sans make a meme so I know

Finally, a true gamer

Lmao I spent ages fighting sans and writing all that down
It only took me 7 tries tho

I've been practising on an emulator and I'm speedrunning the genocide route on my friend's Nintendo switch

I've speedran genocide
My best is no deaths on anything except sans

a true gamer you are

I'm speedrunning true pacifist now

Step 1: become good at the game

Tip one: Dont or follow @Bendy_TheDancingDemon's advice

I'm in the same boat
I gave up and went back to Hello Neighbor

^ \/ < > < > B A Start

Get good

say what now? 7 months? yikes-