Mhammed Talhaouy

Posted on Nov 3

📜 EIP vs ERC — What’s the Difference?

#web3 #blockchain #ethereum #beginners

If you’ve read Ethereum documentation or audited a smart contract, you’ve probably seen words like EIP-1559, ERC-20, or ERC-721.

They look similar — but they’re not the same.

Let’s break down what EIPs and ERCs mean, how they’re related, and why both are essential to Ethereum’s evolution 🔍

⚙️ What Is an EIP?

EIP stands for Ethereum Improvement Proposal.

An EIP is like a blueprint for upgrading Ethereum — it’s how developers propose changes, improvements, or new features to the network.

Think of EIPs as:

“Official documents that describe a new idea, rule, or technical change for Ethereum.”

🧱 Example: EIP-1559 (The Gas Fee Upgrade)

Before EIP-1559, gas fees on Ethereum were unpredictable — users had to guess how much to pay.

EIP-1559 changed that by introducing:

A base fee that gets burned 🔥
A tip (priority fee) for miners
Better fee estimation and user experience

Result: fairer gas pricing, more stable transactions, and partial ETH burn — making ETH slightly deflationary.

📘 EIP-1559 = a change to Ethereum’s protocol itself.

💡 Types of EIPs

There are a few categories:

Type	Description	Example
Core EIP	Changes to Ethereum’s consensus or protocol	EIP-1559 (gas fees)
Networking EIP	Changes to P2P communication between nodes	EIP-1459
Interface EIP (ERC)	Standards for smart contracts and tokens	ERC-20, ERC-721

👉 Notice that last one?
That’s where ERCs come in.

🧩 What Is an ERC?

ERC stands for Ethereum Request for Comment.
It’s a type of EIP, but specifically focused on application-level standards — mostly smart contracts.

In short:

Every ERC is an EIP, but not every EIP is an ERC.

ERCs define rules and interfaces that make contracts work together across the Ethereum ecosystem.

🪙 Example: ERC-20 (Fungible Token Standard)

This defines how fungible tokens (like stablecoins or governance tokens) behave.

Common functions:

function totalSupply() public view returns (uint256);
function balanceOf(address account) public view returns (uint256);
function transfer(address recipient, uint256 amount) public returns (bool);

Any token that follows these rules (like USDC, UNI, DAI) can easily interact with wallets, DEXs, and DeFi protocols.

📘 ERC-20 = EIP that defines a token standard for smart contracts.

🎨 Example: ERC-721 (NFT Standard)

The standard that made NFTs possible!
Defines unique, non-fungible assets — each token has its own ID.

Example projects:

Bored Ape Yacht Club
CryptoPunks
Art Blocks

ERC-721 is also an EIP, but it focuses on NFTs, not protocol upgrades.

⚖️ EIP vs ERC — Key Differences

Feature	EIP	ERC
Full Name	Ethereum Improvement Proposal	Ethereum Request for Comment
Purpose	Propose upgrades to Ethereum itself	Define standards for smart contracts
Scope	Protocol-level	Application-level
Examples	EIP-1559 (gas), EIP-4844 (proto-danksharding)	ERC-20 (tokens), ERC-721 (NFTs)
Created by	Ethereum core devs or researchers	Smart contract developers
Affects	Network rules	DApps, tokens, and contracts

🧠 Why Auditors Should Care

As a security researcher or auditor, understanding EIPs and ERCs is critical because:

ERC standards define expected behavior of contracts.
→ If a contract claims to follow ERC-20 but behaves differently, that’s a red flag.
EIPs can change gas rules, opcodes, or consensus logic, affecting how you audit gas usage or L2 behavior.
Knowing which EIP/feature a protocol depends on helps you assess risk — especially in newer EVM chains.

🧩 Example: When auditing gas refunds or burn mechanisms, you must know if EIP-3529 (reducing gas refunds) applies.

🧬 Relationship Summary

You can think of it like this:

EIP (Ethereum Improvement Proposal)
 ├── Core EIPs (protocol upgrades)
 ├── Networking EIPs
 └── Interface EIPs → ERCs (token & contract standards)

So when you hear “ERC-20” or “ERC-721,” remember — they’re just EIPs that define standards for how smart contracts should behave.

Term	Focus	Example
EIP	Protocol changes or technical proposals	EIP-1559, EIP-4844
ERC	Application-level standards (smart contracts)	ERC-20, ERC-721, ERC-1155
Relation	ERCs are a subset of EIPs	ERC = Interface EIP

🧩 Final Thoughts

Ethereum evolves through community proposals — EIPs and ERCs are how developers, researchers, and auditors collaborate to make it better.

EIPs shape the engine.
ERCs define the rules for the apps that run on that engine.

Understanding both helps you build, audit, and interact with Ethereum more confidently.

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