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ResearchRefactron vs the codemod baseline: see the benchmarks
Refactor Code.

Verify It's Safe
Ship With Confidence.

Refactron safely refactors and modernizes legacy code with behavior-preserving refactoring and deterministic verification.

$ pip install refactron
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Used by developers from

  • UST
  • SalesforceSalesforce
  • KPIT
  • AccentureAccenture
  • PyPi
  • Github
  • Open Source Community

Everything you need to refactor production code safely.

Deterministic, behavior-preserving refactoring with verification, rollback, and documentation built in.

Explore the platform
WORKFLOW

Map every import edge. Surface legacy patterns across the full dependency tree.

How Refactron stays safe in production.

Three guarantees. Verifiable end-to-end. Yours to control.

01VERIFICATION

Verification before every write.

Three gates run before any file is touched: syntax validation, import-graph integrity, and your existing test suite. If any gate fails, the original is untouched.

syntax · sub-50msimports · zero brokentests · must pass
VERIFICATION GATES
3 / 3 PASSED
01
SYNTAX
02
IMPORTS
03
TESTS
SYNTAX12 ms
IMPORTS8 ms
TESTS6.2 s
If any gate fails, the original file is untouched.
97.3%
PASS RATE
02REFACTOR

Finds legacy code. Refactors it structurally.

Deep analysis across the full dependency graph surfaces outdated patterns, deprecated APIs, and architectural debt. Refactron transforms them deterministically. No LLM. No guessing. Same input, same output.

DeterministicNo LLM in the loopIdempotent
DETECTED · REFACTORED
21 PATTERNS
callback chain
→
async / await
×3
var declarations
→
const / let
×12
requests
→
httpx
×4
sync I/O in async
→
awaitable I/O
×2
service.py
STRUCTURAL RENAME
−proc_pmt(c, a)
+process_payment(card: Card, amount: Decimal)
Behavior preserved · 47 tests passed
03CONTROL

You review. You approve. You rollback.

Every structural refactor is a readable before-and-after. Low-risk changes apply automatically. High-risk changes ask first. One command rolls everything back. No git required.

Readable diffRisk-scoredOne-command rollback
CONTROL FLOW
2 PENDING
REVIEW
APPROVE
ROLLBACK
LOW RISKAPPLIED
HIGH RISKAWAITING
One command rolls everything back. No git required.
↺ rollback

How Refactron compares.

Cursor and CodeAnt lean on LLMs. SonarQube analyzes, but it doesn't refactor. Refactron finds legacy code, transforms it deterministically, and verifies before anything touches disk.

CAPABILITIES
Refactron
Cursor
SonarQube
CodeAnt
Finds legacy code
Refactors it structurally
No LLM in the engine
Verifies safety before write
Generates docs after refactor
Runs fully local
LANGUAGE SUPPORT
Python
TypeScript

Read the full research paper →

Comparison reflects publicly documented positioning as of 2026. Refactron is built on deterministic transforms plus verification, not generic lint rules or chat edits.

QUICKSTART

Up and running in 60 seconds.

Node.js 18+

# Install
› npm install -g refactron

# Scan for legacy patterns
› refactron analyze .

# Preview the refactor — nothing is written
› refactron run --dry-run .

# Apply — 3 gates, then atomic write
› refactron run --apply .

That is it. No config. No setup.
No code leaves your machine.

Builders love Refactron.

And they can't stop talking about safer refactors and boring, reviewable diffs.

Sarah Chen

@sarahbuilds

Finally ran refactron analyze on our 4yr-old monolith. The legacy hotspots it surfaced matched what we'd been scared to touch. Local-only was non-negotiable for us.

Jan 12, 2026

Dev Akira

@akira_ts

npm i -g refactron → analyze → preview refactor. My tech lead actually smiled at standup. Unrelated but still counts.

Feb 18, 2026

Sarah Chen

@sarahbuilds

Finally ran refactron analyze on our 4yr-old monolith. The legacy hotspots it surfaced matched what we'd been scared to touch. Local-only was non-negotiable for us.

Jan 12, 2026

Dev Akira

@akira_ts

npm i -g refactron → analyze → preview refactor. My tech lead actually smiled at standup. Unrelated but still counts.

Feb 18, 2026

Marcus Johnson

@mj_codes

The thing that sold me wasn't the diff. It was verify before write. Tests failed once on a proposed extract; disk never changed. That's the bar for production Python.

Feb 3, 2026

^ Principal backend engineer (yes, I read the full trace)

Priya N.

@priyainfra

Security asked "where does code go?" Answer: nowhere. CLI on CI runners with read-only first. Docs after refactor were a nice touch for onboarding.

Feb 8, 2026

Marcus Johnson

@mj_codes

The thing that sold me wasn't the diff. It was verify before write. Tests failed once on a proposed extract; disk never changed. That's the bar for production Python.

Feb 3, 2026

^ Principal backend engineer (yes, I read the full trace)

Priya N.

@priyainfra

Security asked "where does code go?" Answer: nowhere. CLI on CI runners with read-only first. Docs after refactor were a nice touch for onboarding.

Feb 8, 2026

Elena Ruiz

@elenadev

We compared notes with another team using chat-only refactors. Different problem. Refactron is boring in the good way: same command, same shape, reviewable PRs. @refactron

Jan 28, 2026

Jordan Lee

@jordanl_js

TS + Python repo. Still early but the structural suggestions weren't vibes; they were scoped files with a verification story. More of this please.

Jan 22, 2026

Elena Ruiz

@elenadev

We compared notes with another team using chat-only refactors. Different problem. Refactron is boring in the good way: same command, same shape, reviewable PRs. @refactron

Jan 28, 2026

Jordan Lee

@jordanl_js

TS + Python repo. Still early but the structural suggestions weren't vibes; they were scoped files with a verification story. More of this please.

Jan 22, 2026

Simple pricing. Scale when you’re ready.

Start free. Pay when Refactron starts saving real engineering time.

Free (Community)

$0

For individual developers & evaluation

  • Local analysis & legacy code detection
  • Safe-mode refactoring
  • Git diffs & reports
  • Open-source & personal use
Most Popular

Pro (Teams)

$20/ developer / month

For growing engineering teams

14-Day Free Trial
  • Everything in Free
  • Full refactoring engine
  • Verification engine with all three checks
  • Documentation engine
  • CI/CD integration
  • Metrics and technical debt reports
  • Priority updates

Enterprise

Custom

For production & regulated environments

  • Everything in Pro
  • Team management & collaboration
  • On-prem / private deployments
  • Advanced verification controls
  • Audit logs & compliance support
  • Dedicated support

FAQ

No. Every structural refactor is shown as a readable diff. Low-risk changes can apply automatically. High-risk changes always ask for approval first. You are always in control.

DiffApprovalControlSafety

Every refactor goes through verification checks to preserve behavior. Changes are incremental, measurable, and fully reversible.

VerificationSafetyIncrementalReversible

Yes. Refactron is designed for long-lived and production codebases where safety, traceability, and control matter most.

ProductionLegacySafetyTraceability

By default, Refactron runs locally with telemetry disabled. Private and on-prem deployment options are planned for teams with strict security requirements.

PrivacyLocalSecurityOn-Prem

Python, TypeScript, and JavaScript are fully supported today. Go, Rust, and Java are on the roadmap.

PythonTypeScriptJavaScriptRoadmap

The core platform is proprietary. Some tooling and libraries are open for early access and community feedback.

Open SourceProprietaryEarly AccessCommunity

Have a specific question? Let's talk.

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