Securing software is no longer an afterthought; it’s a necessity. As cyber threats evolve, so must the methods we use to identify and fix vulnerabilities in code. With that current situation, 36% of the companies said that Code Reviews are the best way to improve code quality.

Businesses face a choice in achieving secure code: rely on the expertise of manual code reviews or use automated code review tools that scan for issues rapidly and systematically. Each approach brings its unique strengths to the table, but which one provides the protection you need?

Understanding the differences between manual and automated code review is key to making an informed decision. This comparison isn’t just about tech preferences. It’s about choosing the best path for your business’s long-term security.

Below, we’ll break down how each method works, highlight their advantages, and discuss how they can be combined for a comprehensive security strategy.

automated code review illustrations

What is manual code review?

Manual code review involves skilled developers and security experts carefully analyzing the code to find vulnerabilities. It’s a time-intensive process, but it allows experts to dive deeply into each part of the codebase, examining logic, structure, and overall integrity. Human reviewers bring context, experience, and a sharp eye for issues that automated tools might overlook.

Benefits of manual code review

  1. Human insight and context: Manual review brings a level of context that’s hard to replicate with automation. Reviewers understand why the code was written a certain way, which helps them detect issues beyond simple syntax. They catch errors that require a big-picture understanding of the code’s purpose and flow.
  2. Identification of complex security risks: Certain security risks are tricky to spot because they depend on logic or unique flows within the code. Manual reviews are excellent for identifying these complex vulnerabilities, especially those involving business logic or context-specific risks.
  3. Quality and readability improvements: Manual code review often improves more than security. Reviewers may identify ways to make the code cleaner and easier to maintain, which reduces future errors and enhances overall stability.

Limitations of manual code review

  1. Resource and time-intensive: Reviewing each line manually can take days or weeks for large codebases. For applications with rapid updates, the time commitment might not be feasible.
  2. Potential for human error: Even skilled reviewers may overlook certain details, especially when code is long or complex. The risk of human error can impact consistency in catching vulnerabilities.
  3. Higher cost: Manual code review is resource-intensive, involving hours of skilled labor, which may lead to higher costs. Businesses with large codebases or frequent updates may find these costs a limiting factor.

What is automated code review?

Automated code review uses tools that scan code quickly and systematically, flagging potential vulnerabilities based on predefined rules. These tools are built with vast databases of known vulnerabilities, allowing them to check code for common risks with speed and consistency. An automated code review can handle thousands of lines of code in minutes.

Benefits of Automated Code Review

  1. Speed and scalability: Automated code review is fast. It can process large volumes of code in minutes, making it an ideal option for fast-moving projects. Teams receive rapid feedback, which helps them address vulnerabilities without delay.
  2. Consistency and breadth: Automated tools don’t get tired. They cover every line of code with the same thoroughness each time, making them especially valuable for identifying common security flaws across large codebases.
  3. Integration with development pipelines: Many automated code review tools can integrate directly into development environments, which allows developers to receive feedback in real-time as they write code. This constant monitoring helps them catch issues early and fix them on the spot.

Limitations of automated code review

  1. Limited context awareness: Automated tools can miss issues that require a contextual understanding of code. They might flag syntax errors but miss logic errors or issues that depend on specific flows, which limits their ability to find complex vulnerabilities.
  2. False positives: Automated tools can produce false positives, flagging issues that aren’t genuine threats. These can take up time as developers investigate and dismiss these warnings.
  3. Dependence on known vulnerability databases: Most automated code review tools rely on a database of known vulnerabilities, which means they’re great at finding common issues but may miss new or unique security risks specific to the application.

Comparing manual and automated code review

FeatureManual Code ReviewAutomated Code Review
SpeedSlow, requires significant time for large codebasesFast, scans extensive codebases in minutes
Context awarenessHigh, considers intent and purpose of codeLow, limited to syntax and patterns
ConsistencyVariable, can differ by reviewerConsistent, applies rules systematically
CostHigher, depends on skilled laborLower per scan, but tool licensing varies
Error detectionCatches complex, context-based vulnerabilitiesEffective for common, known vulnerabilities
Integration with developmentSeparate from development, often done post-codingIntegrates seamlessly with CI/CD pipelines
False positivesLess likely, relies on human validationMore frequent, may require human follow-up

Why a combined approach often works best

While each approach has its strengths, relying on only one may leave security gaps. Combining manual and automated code review provides a well-rounded security solution.

  1. Enhanced accuracy: Automated tools identify common issues quickly, while manual reviews focus on areas where human insight adds value. Together, these approaches maximize accuracy.
  2. Greater efficiency: Automated reviews can scan code initially, identifying immediate concerns, while manual reviewers prioritize high-risk areas. This combination reduces the time needed for thorough security checks.
  3. Cost-effectiveness: While manual review is more resource-intensive, using it alongside automation focuses its use on the most critical parts of the code. This approach helps control costs without sacrificing security quality.
  4. Continuous monitoring: Automated code review tools can run continuously, providing real-time feedback. Periodic manual reviews offer deeper insights, catching complex issues that automation may miss.

Choosing the right fit for your business

Deciding between manual and automated code review ultimately depends on your business needs and budget. For businesses in sectors like healthcare, fintech, or e-commerce, security is a top priority. A balanced approach, leveraging both automated and manual review, can be a practical solution that addresses both immediate and complex security concerns.

With the right code review strategy, you not only safeguard your software but also protect your business, brand reputation, and customer trust.

A significant 37% of companies report that limited manpower is the biggest obstacle to implementing effective code review. Working with a security partner skilled in both manual and automated code review methods can solve this challenge. S

uch a partner like Sunbytes with our code review service can ensure you get a solution tailored to your business goals and security needs. Contact us today!








Let’s get started with Sunbytes

Drop us a line and we’re just 1 click away to make your projects ready

(Required)
Untitled(Required)
This field is for validation purposes and should be left unchanged.

Blog Overview