Codeflash
Ship Blazing-Fast Python Code — Every Time
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What is Codeflash?
Codeflash is an AI-powered performance optimizer that automatically finds the most performant version of your code through benchmarking while verifying correctness. It uses advanced large language models to generate multiple optimization ideas for your code, tests them to ensure they maintain the same behavior, and benchmarks them for actual performance gains. The tool then creates merge-ready pull requests containing the best optimization found, which developers can review and merge.
Key features include automated function and codebase optimization, continuous optimization through GitHub Actions that reviews every new pull request, deep instrumentation that understands code behavior by executing it, support for Python (primary) and JavaScript/TypeScript, correctness verification through existing and auto-generated regression tests, sandboxed execution ensuring code is never used to train models, and detailed benchmark numbers attached to every PR. The optimizer finds better algorithms, removes wasteful compute, improves logic, utilizes caching, and leverages more efficient library methods without modifying system architecture.
Codeflash is designed for software engineering teams, Python developers, ML/engineering teams running models in production, organizations with high cloud infrastructure costs, and companies using AI-generated code that tends to be slower. It's particularly valuable for teams working on AI agents, computer vision algorithms, PyTorch code, numerical code, backend code, inference/training/data processing workflows, and anyone writing Python who wants to cut infrastructure bills by up to 90% while maintaining peak code efficiency.
Codeflash pricing
Pricing model: Freemium
Free tier: $0/month with no hidden fees, includes 25 function optimization credits/month, community support, public GitHub projects only, local tracing only, and AI training permitted. Pro tier: $20 per user/month with 14-day free trial, includes 500 function optimization credits/user/month, advanced optimizations & developer code quality metrics, priority support, private GitHub projects, zero AI training policy ever, and user dashboard with analytics. Enterprise tier: Custom pricing, includes unlimited optimization credits, zero AI training policy ever, admin usage analytics, on-premises deployment, 24/7 premium support, custom SLAs on optimizations suggested, and onboarding setup with finding optimizations.
Codeflash pros
- Automatically finds fastest version of code through AI-powered benchmarking
- Verifies correctness before applying any optimization
- Creates merge-ready pull requests with benchmark numbers
- Cuts infrastructure bills by up to 90%
- Continuous optimization via GitHub Actions for every new PR
- Supports Python, JavaScript, and TypeScript
- Deep instrumentation understands code behavior by executing it
- Finds optimizations humans would miss (global and superhuman)
- Rewrites multi-step flows to fewer steps, not just small tweaks
- Zero data retention policy - code never used to train models
- Sandboxed execution with no production access required
- Includes 14-day free trial on Pro plan
- Senior performance engineers review every optimization before shipping
- SOC 2 Type 2 certified for enterprise security
- Improves individual functions by 10% to 5000x speedup
- End-to-end workflow improvements up to 35% faster
- Auto-generates regression tests to verify correctness
- Integrates with Claude Code, Cursor, and GitHub
- Provides detailed explanation of changes with proof of correctness
- On-premises deployment option available for Enterprise
Codeflash cons
- Currently only optimizes Python in production (JS/TS support limited)
- Free tier limited to 25 function optimization credits per month
- Pro plan at $20/user/month may be expensive for small teams
- Optimizing entire codebase can take a while for large projects
- Free tier only supports public GitHub projects, not private
- Free tier allows AI training on your code (removed in Pro)
- Local tracing only on free tier, not full optimization
- No custom SLAs on free or Pro tiers (Enterprise only)
- Requires existing test suite for best correctness verification
- Enterprise pricing is custom (not transparent)
- May not modify system architecture, only current implementation
- 14-day trial required before Pro plan commitment
- Advanced optimizations only available on Pro tier and above
- Community support only on free plan (priority on Pro)
- GitHub Actions integration required for continuous optimization
Frequently asked questions about Codeflash
How is Codeflash different from other AI copilots?
Codeflash implements expert optimization workflows with deep instrumentation that understands everything about a code's behavior and performance by executing it. This way Codeflash generates such high quality, correct optimizations that optimization can be automated for all new code, unlike other AI copilots that may not verify correctness or benchmark actual performance gains.
How much faster can my code get?
Individual functions can speed up anywhere between 10% to 5000x. Codeflash has improved professional workflows—even those already manually optimized and used millions of times daily—by up to 35% end-to-end. Think of it as an expert Python developer rewriting your code without changing behavior, and Codeflash often matches or exceeds that performance.
Does Codeflash optimize any language other than Python?
Codeflash currently only optimizes performance for Python in production, although this might change in the future. The documentation mentions JavaScript and TypeScript support, but Python remains the primary and most fully-optimized language.
How does Codeflash verify correctness?
Codeflash verifies correctness by generating and running new regression tests, as well as any existing tests you may already have. It ensures your code behaves the same way before and after optimization, offering high confidence that behavior remains unchanged. Every change is checked against existing tests and auto-generated regression tests.
What is Continuous Optimization and how does it work?
Continuous Optimization is Codeflash's main usage model where you install it as a GitHub Action to optimize new code on every pull request. When Codeflash finds an optimization, it asks you to review it with a detailed explanation of changes, including percentage speed increase and proofs of correctness. This ensures your code, your team's code, and AI agent code stays optimized before causing performance regressions.
Is my code safe with Codeflash?
Yes. Codeflash runs in a sandboxed environment with no production access and no exfiltration paths. They have a Zero Data Retention Policy and never train on your code—not theirs, not third-party, ever. They are also SOC 2 Type 2 certified with annual audits and continuous controls.
How does an engagement with Codeflash run?
An engagement runs in four steps: (1) Scope - pick your objective (cost, p99 latency, cold start, GPU utilization) and reproduce baseline on representative workload; (2) Optimize - Codeflash-agent explores autonomously in sandbox while humans steer it; (3) Review - performance engineers audit every optimization and only PRs passing quality bar reach your team; (4) Continuous - agent stays on to optimize every new PR and catch regressions where introduced.
What kind of optimizations does Codeflash find?
Codeflash finds better algorithms, opportunities to remove wasteful compute, better logic, utilization of caching, and more efficient library methods. It can rewrite 6-step flows as 3-step flows, not just small tweaks. Optimizations include GPU optimization, custom CUDA kernels, and algorithmic rewrites, particularly for ML workloads including inference, training, and data processing.
Who is Codeflash best for?
Codeflash is best for software engineering teams who want expert-level performance tuning automatically, Python developers tired of manual optimization work, organizations with high cloud infrastructure costs that can be cut 40-90%, ML teams running models in production (vision models, vLLM, Hugging Face Diffusers), and companies using AI-generated code that tends to be slower than necessary.
How do I get support or report bugs?
For questions or suggestions, use the Intercom button in the lower right, join their Discord, email [email protected], or ping through the chat button. To report bugs, open a new issue at their GitHub repository. For enterprise customers, they create a shared Slack channel for priority support.