I think you'll agree with me when I say that a dog pulling on their leash is something that doesn't make going for a walk fun at all. And that's probably how your dog feels as well.
Here are the top reasons why your dog is pulling on their leash and some quick tips to prevent and address each point.
1. Over-excitement/pent-up energy The line above says it all! And it can be hard sometimes to differentiate between this point and the following one. An overly excited dog is one that is either triggered by the act of going for a walk because they have through time learned that going for a walk is where they can and will get to feel this way WHILE they get to start and continue walking. There's a lot you can do to start changing that today! Start breaking down the amount of time you normally plan to spend on a walk and use 80-90% of that time doing indoor activities that will help your dog feel calm by the time it's time to go for a short & sweet, calm walk. Indoor activities can consist of tug & pull games, indoor/backyard agility games, nosework & snuffle/puzzle toys. 2. Reacting to a trigger A trigger while on a walk can be anything that'll get your dog pulling, in any direction. Whether it's towards a dog, or away from a loud car, ensuring that we first pick up on a change in our dog's body language (stiff body, perked up ears, long staring/locked eyes) will allow us to then redirect our dog towards a different feeling by showing them that they can refocus on us and lighten up as we walk away, with the help of a fun toy or a few pieces of a rare treat that get tossed in the direction you rather walk towards, calmly. If this behaviour happens early on walks, perhaps even as soon as you leave the doorstep, it's ideal that we work on very short 'going outside' sessions first, by walking in and out of the house and rewarding with food, to allow your dog to let you know when they feel more calm and relaxed prior to proceeding. 3. Overly tired Long walks and/or very mentally stimulating walks (both physically AND mentally) can cause a dog to act differently and in a more difficult manner, as they should at that moment already be back indoors relaxing, enjoying a stuffed Kong, instead of being outside on a walk if they don't yet fully know how to best regulate their own emotions at that point. Work on paying close attention to what amount of time your dog feels the most relaxed outside before they start acting differently while walking, as that'll usually be a good indicator of what their limit is, thus allowing us to move forward with shorter walks daily, to avoid walking an overly tired dog. To end things, please know that pulling is not due to the tool you use but rather a feeling, as you can see from the three points above. That said, a tool that is harm-free, safe, comfortable, and useful is freedom harnesses if you wanted to be even more prepared to work on preventing and managing a dog that pulls on walks.