Most SAST tools read source code, and some accept compiled output such as bytecode or binaries. Support varies by tool and language. OWASP lists "can it run against binaries instead of source?" as a selection question, so ask each vendor for a specific answer for your languages.
Why the input matters
Source code carries names, structure and comments that make analysis easier. A compiled artifact is closer to what runs, which helps in cases where you do not have the source, but it loses detail. OWASP also notes that many tools have difficulty analyzing code that cannot be compiled, because analysts often lack the right libraries, build instructions or complete code.
So there are two separate questions: does the tool need to compile your code, and can it analyze compiled output when you have no source?
Three situations where the answer changes
- You build everything in house. Source scanning is usually the natural choice, and you can decide whether a build is required.
- You receive a vendor deliverable with no source. A tool that accepts compiled output may be the only way to analyze it, though depth can be limited.
- You ship a mix of languages. One tool may accept source for some and compiled output for others.
If you are in the second situation, be careful with expectations. Findings from a binary may be harder to trace back to a line your developers can edit.
Questions to ask the vendor
| Question | Why it matters |
|---|---|
| Which languages can be scanned from source alone? | Avoids a build requirement you cannot meet |
| Which can be scanned from bytecode or binaries? | Covers code you did not write |
| Does a binary finding map to a source location? | Affects how fixable the result is |
| Does the tool need dependencies resolved? | Affects scan setup in CI |
| What changes if the build fails? | Shows how the tool degrades |
Write the answers down by language. A single "yes" for the whole product usually hides exceptions.
A related distinction
Scanning compiled code in your own application is different from scanning the libraries it uses. Dependency scanning, often called software composition analysis, looks at the third party packages and their known vulnerabilities. It answers a different question and does not replace analysis of your own logic.
How to test it
Take one small service. Scan it from source. Then, if the tool supports it, scan the built artifact. Compare the findings, and note the ones that appear in only one mode. The comparison tells you what you gain or lose, using your code instead of a brochure.
A worked example: three inputs for one service
Take a small service with a Java style build. You have the source repository, a built archive of compiled classes, and a container image that includes the archive and its libraries. A scanning approach can read any of the three, and each gives a different view.
| Input | What the tool can see | Typical limits |
|---|---|---|
| Source repository | Names, structure, comments, build files | May need a working build, may skip generated code |
| Compiled archive | Compiled code, often with some names preserved | Less context, line mapping may be approximate |
| Container image | Everything packaged, including libraries and files | Mixes your code with third party code |
A tool that reads source gives findings with exact lines, which developers can act on quickly. A tool that reads compiled output can help when source is not available, but the mapping from finding to editable line may be weaker. A container scan answers a different question, mostly about packages inside the image.
Why the build requirement is the hidden cost
OWASP lists "does it require a fully buildable set of source?" as a selection criterion and notes that analysts often cannot compile code because they lack the right libraries, build instructions or the full source. For your own repositories, this is usually solvable, but it has a cost: someone has to make the build reproducible inside the scanning environment.
Ask these practical questions during a pilot:
- How long did it take to get the first successful scan on each repository?
- Which repositories needed special build steps?
- What happens on a pull request when a dependency fails to download?
- Does a failed build produce a partial scan or no scan?
A tool that fails silently on a broken build is worse than one that fails loudly. Silent failure creates a false sense of coverage.
Step by step: choose an input strategy
- List your repositories and mark which have working, reproducible builds.
- List any code you must scan without source, such as vendor deliverables.
- For the first group, prefer source scanning and require the vendor to show the build setup.
- For the second group, ask the vendor which binary formats it supports and what depth to expect.
- Write down the expected limits for each group, so nobody assumes equal depth everywhere.
- After the pilot, compare actual results with those expectations.
The compiled code question for third party software
Teams sometimes want to scan software they bought, to see what is inside. That is a different problem from scanning code you own. A binary tool may report weaknesses in the vendor's code, but you cannot fix them yourself, so the useful output is evidence for a conversation with the vendor. In that case, an inventory of components, often called an SBOM, and a list of known vulnerabilities in those components may give you more actionable information than a deep scan of the vendor's own logic.
What to record about your choice
Write a short note in your tool evaluation file: which input types the tool supports for each language, which you will use, and which gaps you accept. When a security reviewer asks "does it cover our legacy services?", you can answer from the note instead of from memory.
A caution on marketing language
"Binary analysis" can describe several things: reading bytecode of a managed language, analyzing machine code, or inspecting packaged libraries. They are not equivalent. Ask for the exact formats and languages supported, and ask to see a sample finding from each.
Try it yourself
Click through it at your own pace, or open it full screen. Look at how each finding points to a place in code, and think about how that would look if only compiled output were scanned.
Quick check
Is binary analysis always better because it sees what runs?
Not always. It can help when source is missing, but findings may be harder to map back to code a developer can change.
Do I need to build my code before a SAST scan?
It depends on the tool and language. Some need a build, some read source directly. Ask for the answer per language.
Is scanning a container image the same as SAST?
No. A container scan mostly inventories packages and known vulnerabilities in the image. SAST analyzes code logic for weaknesses. They answer different questions.
Safeguard offers SBOM and dependency scanning for the packages your software uses, and a free scan is at gold.safeguard.sh/scan.
Sources
Last reviewed: 19 October 2026.
