Pimlico excels at developer experience and high-performance infrastructure, leveraging its deep integration with the Alchemy RPC stack. This provides a seamless path for teams already using Alchemy for node services. For example, Pimlico's bundler boasts >99.9% uptime and supports advanced features like ERC-20 and ERC-721 gas sponsorship out-of-the-box, which is critical for onboarding mainstream users. Their pimlico.json configuration standard simplifies setup.
LABS
Comparisons
Pimlico Bundler vs. Stackup Bundler: The Technical Showdown
A data-driven comparison of two leading Bundler-as-a-Service providers for ERC-4337 account abstraction. We evaluate reliability, supported chains, feature sets, and integration models to help technical leaders choose the right infrastructure.
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introduction
THE ANALYSIS
Introduction: The Bundler Infrastructure Battle
A data-driven comparison of Pimlico and Stackup, the leading infrastructure providers for ERC-4337 bundlers.
Stackup takes a different, more decentralized approach by building on a permissionless, open-source validator network. This strategy results in a trade-off: while potentially offering greater censorship resistance and network resilience, it may involve more initial configuration complexity for developers. Stackup's architecture is designed for protocols that prioritize decentralization and want to avoid vendor lock-in to a single infrastructure provider's stack.
The key trade-off: If your priority is rapid deployment, maximal reliability, and a tightly integrated feature set (like Paymaster services), choose Pimlico. If you prioritize decentralized infrastructure, protocol-level control, and avoiding centralized dependencies, choose Stackup. Your decision hinges on whether optimized developer velocity or architectural sovereignty is the higher-order bit for your project.
tldr-summary
Pimlico vs. Stackup
TL;DR: Key Differentiators at a Glance
A high-level comparison of the two leading ERC-4337 bundler services, highlighting their core architectural and strategic differences.
01
Pimlico: Superior Developer Experience & Integration
Deep SDK & Tooling: Offers permissionless.js and userop.js for streamlined integration. This matters for teams wanting to launch user operations quickly with minimal custom code.
Paymaster-First Strategy: Tight integration with its own Pimlico Paymaster and ERC-20 gas sponsorship. This matters for projects focused on abstracting gas fees for end-users.
02
Pimlico: Aggressive Multi-Chain Expansion
Broad Network Support: Live on 15+ networks including Base, Optimism, and Arbitrum. This matters for protocols deploying on emerging L2 ecosystems. Unified API: Single endpoint abstraction across all supported chains. This matters for developers building cross-chain applications who want to avoid managing multiple bundler instances.
03
Stackup: Battle-Tested Reliability & Decentralization
Longest Production History: One of the first ERC-4337 bundlers, processing millions of user operations. This matters for mission-critical applications where uptime is non-negotiable. Decentralized Relayer Network: Operates a permissionless network of relayers, enhancing censorship resistance. This matters for protocols prioritizing credible neutrality and long-term infrastructure resilience.
04
Stackup: Flexible Gas Management & MEV Strategies
Advanced Gas Policies: Configurable fee markets and priority queues for user operations. This matters for high-frequency dApps needing predictable inclusion times. MEV Protection Focus: Implements strategies like time-boost auctions to reduce extractable value. This matters for protecting users from front-running and ensuring fair transaction ordering.
HEAD-TO-HEAD COMPARISON
Feature Matrix: Pimlico vs. Stackup Bundler
Direct comparison of key metrics and features for ERC-4337 bundler services.
| Metric | Pimlico Bundler | Stackup Bundler |
|---|---|---|
ERC-4337 Spec Compliance | ||
Native Paymaster Integration | ||
Gas Sponsorship API | ||
Supported EntryPoints | v0.6, v0.7 | v0.6 |
Multi-Chain Support | Ethereum, Polygon, Base, 10+ | Ethereum, Polygon, Arbitrum, 6+ |
Bundler Uptime SLA | 99.9% | 99.5% |
Pricing Model | Pay-as-you-go + Subscription | Pay-as-you-go |
Public RPC Endpoint |
PERFORMANCE & RELIABILITY BENCHMARKS
Pimlico Bundler vs. Stackup Bundler
Direct comparison of key metrics and features for ERC-4337 bundler infrastructure.
| Metric | Pimlico Bundler | Stackup Bundler |
|---|---|---|
Avg. UserOp Inclusion Time (Mainnet) | < 5 sec | < 12 sec |
Public RPC Endpoint SLA | 99.5% | 99.9% |
Supported EntryPoint Versions | v0.6, v0.7 | v0.6 |
Native Paymaster Integration | ||
Gas Sponsor (Pay-as-a-Service) | ||
Multi-Chain Support (Networks) | 10+ | 6+ |
Max Bundle Size (UserOps) | Unlimited | 50 per bundle |
pros-cons-a
STRENGTHS AND WEAKNESSES
Pimlico Bundler vs. Stackup Bundler
A data-driven comparison of two leading ERC-4337 bundlers for CTOs and architects. Key differentiators in infrastructure, fee models, and ecosystem integration.
02
Pimlico's Weakness: Centralized Relayer Dependency
Primary service relies on a centralized, managed relayer infrastructure, creating a potential single point of failure. While open-source, self-hosting requires significant operational overhead. This matters for protocols prioritizing maximum decentralization and censorship resistance above convenience.
04
Stackup's Weakness: Less Turnkey Ecosystem Tooling
While robust, the ecosystem (paymasters, signers) is less integrated by default compared to Pimlico's full-stack offering. Teams may need to assemble more components (e.g., integrating a separate paymaster like Biconomy). This matters for startups or small teams seeking a single-vendor, batteries-included solution for faster time-to-market.
06
Stackup's Strength: Mempool Strategy & Efficiency
Advanced mempool management and transaction ordering algorithms designed for optimal fee efficiency and inclusion. Strong focus on MEV protection and fair ordering. This matters for applications with high transaction volume (e.g., NFT marketplaces, perp DEXs) where gas cost predictability is critical.
pros-cons-b
Pimlico vs. Stackup
Stackup Bundler: Strengths and Weaknesses
A technical breakdown of two leading ERC-4337 bundler services, highlighting key differentiators for protocol architects and engineering leads.
02
Pimlico: Advanced Gas Management
Specific advantage: Proprietary gas estimation algorithms and multi-chain fee optimization. This matters for protocols operating on Ethereum L1 and high-throughput L2s like Arbitrum and Optimism, where minimizing failed transactions and gas overhead is critical for user retention.
< 1 sec
Avg. Gas Estimation
04
Stackup: Transparent & Open-Source
Specific advantage: Fully open-source bundler client (stackup.sh/stackup-bundler) and public RPC endpoints. This matters for security-conscious teams who require auditability and want to avoid vendor lock-in. It enables self-hosting and deep customization.
CHOOSE YOUR PRIORITY
Decision Framework: Which Bundler For Your Use Case?
Pimlico for DeFi
Verdict: The go-to for high-value, complex transactions and maximal extractable value (MEV) protection. Strengths: Deep integration with Ethereum's DeFi ecosystem (Uniswap, Aave, Compound) via ERC-20 Paymasters for gas abstraction. Offers Permissionless and ERC-7677-compliant operation, crucial for protocol-level integrations. Its Smart Accounts (e.g., Safe, Biconomy) support enables advanced multi-sig and social recovery flows. Pimlico's bundler is battle-tested for high TVL applications where security and reliability are paramount.
Stackup for DeFi
Verdict: A strong, cost-effective alternative for mainstream DeFi dApps prioritizing user onboarding. Strengths: Renowned for low, predictable fees and a robust Paymaster infrastructure supporting ERC-20 and subscription-based gas sponsorship. Its UserOperation mempool explorer provides excellent transparency. Stackup's high reliability and global node distribution ensure consistent performance for high-volume, lower-value DeFi interactions like swaps and deposits.
verdict
THE ANALYSIS
Final Verdict and Recommendation
A data-driven breakdown of the core architectural trade-offs between Pimlico and Stackup to guide your bundler selection.
Pimlico excels at developer experience and gas optimization for high-volume dApps because of its deep integration with the ERC-4337 ecosystem and its proprietary userOperation gas estimation engine. For example, its PimlicoVerifyingPaymaster and seamless support for account abstraction SDKs like Privy and Dynamic reduce integration time from weeks to days. Its infrastructure consistently processes over 500,000 user operations monthly, demonstrating proven scalability for protocols like Friend.tech and Uniswap.
Stackup takes a different approach by prioritizing maximal decentralization and censorship resistance through its open, permissionless node network. This results in a trade-off: while it offers superior credibly neutral infrastructure aligned with Ethereum's core values, its gas estimation can be less aggressive than Pimlico's, potentially leading to slightly higher user costs in exchange for unparalleled reliability and a trust-minimized architecture for protocols like Ethereum Name Service (ENS).
The key trade-off: If your priority is rapid integration, optimized gas fees, and a full-stack AA toolkit for a consumer-facing application, choose Pimlico. If you prioritize decentralization, censorship resistance, and building on credibly neutral infrastructure as a core protocol value, choose Stackup. For most CTOs building mainstream dApps, Pimlico's turnkey solution offers the fastest path to market. For protocol architects where infrastructure trust assumptions are critical, Stackup's permissionless network is the definitive choice.
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