act101 vs Sourcery: Which is Better in 2026?
A comprehensive comparison of act101 and Sourcery covering features, pricing, use cases, and which tool is the right choice for your needs.
⚡ Quick Verdict
Choose act101 if:
- →You need 41 analyzers for dead code, cycles, coupling, hotspots, and seams or 183 deterministic cross-file refactors in a single invocation
Choose Sourcery if:
- →You want more affordable paid plans (from $12/mo)
- →You need line-by-line automated pull-request review or summaries and diagrams of code changes for faster orientation
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act101 vs Sourcery: At a Glance
Pricing Comparison: act101 vs Sourcery
Understanding the pricing differences between act101 and Sourcery is crucial for making the right choice. Here's how their plans compare side by side.
act101 Pricing
Sourcery Pricing
💡 Pricing takeaway: Both act101 and Sourcery offer free tiers, making it easy to try before you buy. Compare the specific plans to find the best value for your use case.
Feature-by-Feature Comparison
Here's how every feature from act101 and Sourcery stacks up.
What Makes Each Tool Unique
🔵 Unique to act101
Features available in act101 but not in Sourcery:
- ✓41 analyzers for dead code, cycles, coupling, hotspots, and seams
- ✓183 deterministic cross-file refactors in a single invocation
- ✓`act gate` returns MERGE / REVIEW / BLOCK with a signed receipt
- ✓Finds the tests that actually reach a changed function before verdict
- ✓Checkpoint-backed `act history undo` for one-command rollback
- ✓163 language grammars, exposed over both MCP and CLI
🟣 Unique to Sourcery
Features available in Sourcery but not in act101:
- ✓Line-by-line automated pull-request review
- ✓Summaries and diagrams of code changes for faster orientation
- ✓Security scanning with per-tier repository coverage and cadence
- ✓Custom review rules
- ✓Works in VS Code and PyCharm as well as GitHub and GitLab
- ✓Bring-your-own-LLM on the Team tier
Use Case Recommendations
Best for: act101
act101 is a native binary that wraps a determinism layer around AI-written code changes, addressing the specific failure mode where the diff is green, the tests pass, and the architecture is quietly worse than yesterday. It runs a three-stage loop. Analyze offers forty-one analyzers covering dead code, dependency cycles, coupling, hotspots, and seams — mapping the structure before anything touches it. Act performs 183 deterministic refactors including rename, extract, inline, move, wrap, introduce, and modernize, applied cross-file in one invocation and reported as structured JSON with a checkpoint id. Attest supplies six verify operations plus `act gate`, which classifies each changed function, finds the tests that actually reach it, diffs the side effects, and returns a deterministic MERGE, REVIEW, or BLOCK verdict with a signed receipt. The distinction the tool draws is between a format-only change (which clears the gate) and a behavior change covered by tests (which routes to a human and is never auto-merged). Because every operation writes a checkpoint, `act history undo` gives you the "undo the last three agent actions" that git archaeology otherwise cannot. It covers 163 language grammars and exposes both an MCP server and a CLI, so an agent can drive it directly. There is also act101 online, a GitHub-native AI-code health scanner for repos your agent writes.
Ideal use cases:
- •Teams or individuals who need 41 analyzers for dead code, cycles, coupling, hotspots, and seams
- •Teams or individuals who need 183 deterministic cross-file refactors in a single invocation
- •Teams or individuals who need `act gate` returns merge / review / block with a signed receipt
- •Teams or individuals who need finds the tests that actually reach a changed function before verdict
- •Anyone focused on refactoring workflows
- •Anyone focused on code review workflows
Best for: Sourcery
Sourcery is an automated code review service built for the situation where AI writes most of the code and human review becomes the bottleneck. Its diagnosis is specific: AI raises output volume, which lengthens the pull-request queue, and the pressure to clear that queue is exactly when security gaps, dependency risks and logic errors slip through. So it reviews line by line on every pull request, produces summaries and diagrams of what changed so a reviewer can orient before reading the diff, and enforces custom review rules you define. Alongside review it runs security scanning, with the scan cadence and repository coverage escalating by tier — limited scans across three repositories biweekly on the free plan, ten repositories on Pro, and 200-plus repositories scanned daily with unlimited issue remediation on Team. It works in the IDE (VS Code, PyCharm) as well as in GitHub and GitLab, and Team adds repository analytics, triple the review rate limits and bring-your-own-LLM. Sourcery is completely free on public repositories, which makes it easy for an open-source maintainer to adopt before paying anything. On code handling the company is explicit: requests pass through third-party model providers but no code or messages are stored, and no provider trains on the data.
Ideal use cases:
- •Teams or individuals who need line-by-line automated pull-request review
- •Teams or individuals who need summaries and diagrams of code changes for faster orientation
- •Teams or individuals who need security scanning with per-tier repository coverage and cadence
- •Teams or individuals who need custom review rules
- •Anyone focused on code-review workflows
- •Anyone focused on security-scanning workflows
💻 Other Coding & Development Tools to Consider
act101 and Sourcery aren't the only options. Here are other popular tools in the same space:
Cursor
AI-first code editor with powerful inline generation
GitHub Copilot
AI pair programmer for code suggestions
Windsurf
AI-native IDE with autonomous coding agents
v0
Generate React UI components from text prompts
Bolt
AI full-stack app builder with instant preview
Devin
Autonomous AI software engineer for full projects
Is one of these your tool?
This page ranks for "act101 vs Sourcery" — buyers comparing the two land here, and ChatGPT and Perplexity cite it. Claim your listing for $19 one-time — no subscription, nothing to cancel — and get a Featured badge, top placement in your category, and a permanent dofollow backlink. Prefer it ongoing? Monthly is one click away on the next page.
Frequently Asked Questions
Is act101 better than Sourcery?
It depends on your needs. act101 offers 6 key features including 41 analyzers for dead code, cycles, coupling, hotspots, and seams and 183 deterministic cross-file refactors in a single invocation, while Sourcery provides 6 features including Line-by-line automated pull-request review and Summaries and diagrams of code changes for faster orientation. act101 uses a freemium model with a free tier, while Sourcery is freemium with free access available. Choose based on which features and pricing model align with your requirements.
Is act101 cheaper than Sourcery?
Sourcery is cheaper, starting at $12/month compared to act101's $29/month. Both tools offer free tiers, so you can try each before committing. Always check the official websites for the most current pricing.
Can I use act101 and Sourcery together?
Yes, many users combine act101 and Sourcery in their workflow. act101 excels at 41 analyzers for dead code, cycles, coupling, hotspots, and seams, while Sourcery shines with line-by-line automated pull-request review. Using both allows you to leverage the strengths of each tool, though this means managing two subscriptions — though free tiers can help manage costs.
What's the main difference between act101 and Sourcery?
While both are coding & development tools, act101 emphasizes 41 analyzers for dead code, cycles, coupling, hotspots, and seams, whereas Sourcery is known for line-by-line automated pull-request review. The best choice depends on your specific workflow and feature priorities.
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