⚡ “RecyclerView Just Got Smarter: DiffUtil vs ListAdapter Showdown”

Vaibhav Shakya | Mr Neo

3 min read

·

Jul 30, 2025

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The Struggle: “Why is my RecyclerView acting like Windows 98?”

Picture this:
I was working on a RecyclerView that showed a list of users.
Every time I got fresh data from the server, I did the obvious thing:

users = newList
notifyDataSetChanged()

And it worked… sort of.

Except the entire list blinked like a strobe light at a rave party 🎉.
Smooth animations? Gone. Performance? Down the drain.
Users? Confused. Me? Crying in the corner. 😭

That’s when someone whispered:

“Bro, ever heard of DiffUtil?”

Round 1: The Manual DiffUtil Ceremony

So I dived in. And DiffUtil was… powerful. But also needy.

I had to create a whole callback class just to compare old vs new lists:

class UserDiffCallback(
    private val oldList: List<User>,
    private val newList: List<User>
) : DiffUtil.Callback() {
    
    override fun getOldListSize() = oldList.size
    override fun getNewListSize() = newList.size
    
    override fun areItemsTheSame(oldPos: Int, newPos: Int) =
        oldList[oldPos].id == newList[newPos].id
    
    override fun areContentsTheSame(oldPos: Int, newPos: Int) =
        oldList[oldPos] == newList[newPos]
}

And then in my adapter:

fun updateUsers(newUsers: List<User>) {
    val diffResult = DiffUtil.calculateDiff(UserDiffCallback(users, newUsers))
    users = newUsers
    diffResult.dispatchUpdatesTo(this)
}

✅ Smooth animations!
✅ Only updated what changed!
❌ Boilerplate like crazy. Felt like I was doing rituals to please RecyclerView gods 🐐.

Round 2: The ListAdapter Glow-Up ✨

Just when I was about to lose hope, I stumbled across ListAdapter.

And let me tell you…
It was like upgrading from Windows 98 to macOS overnight.

No more juggling old/new lists. No more manual dispatching.
Just define a comparison strategy once, and call submitList() like a boss.

class UserDiffCallback : DiffUtil.ItemCallback<User>() {
    override fun areItemsTheSame(oldItem: User, newItem: User) =
        oldItem.id == newItem.id
    override fun areContentsTheSame(oldItem: User, newItem: User) =
        oldItem == newItem
}
class UserAdapter : ListAdapter<User, UserAdapter.UserViewHolder>(UserDiffCallback()) {
    class UserViewHolder(val binding: ItemUserBinding) :
        RecyclerView.ViewHolder(binding.root)
    override fun onBindViewHolder(holder: UserViewHolder, position: Int) {
        val user = getItem(position) // 🚀 No manual list management
        holder.binding.userName.text = user.name
    }
}

Usage? Easy.

adapter.submitList(newList)

Done. Clean. Elegant. No goat sacrifices required 🐐✨.

Side-by-Side Reality Check 🥊

FeatureManual DiffUtilListAdapterBoilerplateLots of codeMinimalAnimations✅✅List ManagementYou handle itAuto-handledUpdate CallupdateUsers(newList)submitList(newList)Sanity LevelLow 😵High 😌

But Wait 🤔 — What if I Don’t Want Diffing?

If you really don’t care about diffs and just want a brute-force reload…
You can give ListAdapter a dummy callback:

class AlwaysDifferentCallback<T> : DiffUtil.ItemCallback<T>() {
    override fun areItemsTheSame(oldItem: T, newItem: T) = false
    override fun areContentsTheSame(oldItem: T, newItem: T) = false
}

But then every update = full refresh = no better than notifyDataSetChanged().
Basically: you’re trolling yourself. 🙃

🎯 Final Verdict

• If you’re maintaining old code → manual DiffUtil is fine.
• If you’re starting fresh → go ListAdapter and don’t look back.

For me? I’ve moved on.
RecyclerView deserves love, not abuse ❤️.

👉 What about you?
Are you still stuck in manual DiffUtil land, or have you embraced the ListAdapter life?

⚡ Next time you see someone using notifyDataSetChanged(), send them this post. Save a RecyclerView today. 😅