Zamzar is one of the oldest file conversion services on the internet — launched in 2006, with over 1,200 supported formats and a reputation built on reliability. For most conversion tasks, that track record is deserved. But Zamzar was built for a world where Excel files were data containers, not executable environments.
In 2026, a large fraction of business-critical Excel files are XLSM or XLSB — they contain VBA macros, worksheet event handlers, and automation code that makes the spreadsheet a functional tool rather than a static table. When you upload these files to Zamzar, the format conversion works. The macros do not survive.
This comparison examines exactly what each service does with macro-containing files, who each tool is built for, and when you should choose one over the other.
| Feature | Macro-Safe Converter | Zamzar | |---|---|---| | VBA macro preservation | Full — macros extracted and packaged with output | None — macros silently dropped | | Free tier | Included (trial conversions) | 2 files/day, 50MB limit | | Paid plans | $9/month membership | $9/month (Basic), $18/month (Pro) | | API available | Via membership | Yes (Basic plan and up) | | Batch conversion | Yes | Yes (paid) | | Max file size | 50MB | 150MB (Pro), 50MB (Basic) | | Output delivery | Instant download + ZIP manifest | Email or direct download | | Supported formats | Excel macro formats (XLSM, XLAM, DOCM, XLSB) | 1,200+ formats | | Primary use case | Macro-safe Excel workflows | General-purpose format conversion |
Summary: Zamzar is the better choice for broad format conversion across document, audio, video, and image formats. Macro-Safe Converter is the only choice when VBA macro preservation is required.
Zamzar's strength — supporting over 1,200 file formats — is also the source of its macro limitation. Supporting that many formats requires a generalised conversion pipeline. The pipeline ingests files, identifies format, applies a conversion transformation, and outputs the target format. This process treats file contents as data to be re-encoded, not as executable structures to be preserved.
VBA macros in Excel are stored in the file's OLE compound document structure as compiled p-code plus human-readable source. A generalised converter that transforms XLSM → XLSX treats the macro modules as non-essential metadata. LibreOffice (which Zamzar uses for Office conversions) does not expose VBA module preservation as a configurable export option for cloud-based conversion pipelines.
The result: a clean, correctly-formatted output with zero macro code.
Zamzar's documentation does not mention this. Their XLSM conversion page does not include a warning about macro stripping. Most users discover the problem after the fact, when they open the output file and find the macros are gone.
Macro-Safe Converter does not try to be a general-purpose converter. It is purpose-built for one workflow: convert macro-containing Excel files while keeping the VBA code accessible.
The technical approach:
1. Pre-conversion extraction: Before any format transformation, the converter extracts all VBA modules from the source file's OLE structure. Standard modules, class modules, UserForm code, worksheet-level code, and workbook-level code are all captured separately.
2. Format conversion: The visual content (cell values, formatting, charts, ranges) is converted to the target format using a validated rendering pipeline. This step is identical to what Zamzar or any competitor does.
3. Output packaging: The output is a ZIP containing:
- The converted file (PDF, XLSX, or other target format)
- All .bas files (one per VBA module)
- A manifest.json documenting module names, line counts, and module types
- A README.txt explaining how to reimport the .bas files into a new XLSM
This approach means the visual conversion quality is equivalent to Zamzar's. The difference is entirely in what's included in the output package.
.bas extraction output for code review, documentation, or version control of VBA modulesIf you're building an application that accepts Excel file uploads from users, the Zamzar API is a legitimate choice for most file types. Here's what the difference looks like when XLSM files enter the pipeline:
Zamzar API pipeline (XLSM → PDF):
Upload file
curl -X POST "https://api.zamzar.com/v1/jobs/" \
-u "API_KEY:" \
-F "source_file=@report.xlsm" \
-F "target_format=pdf"
Result: PDF file, VBA modules absent, no warning in API response
Your users file a support ticket: "where are my macros?"
Macro-Safe Converter API pipeline (XLSM → PDF):
Upload file
curl -X POST "https://api.macrosafe.io/v1/convert" \
-H "Authorization: Bearer MEMBERSHIP_TOKEN" \
-F "file=@report.xlsm" \
-F "target_format=pdf" \
-F "extract_vba=true"
Result: ZIP with PDF + .bas files + manifest.json
Your users receive their macros intact. No support ticket.
For a SaaS product that processes Excel automation files, the API difference alone justifies the tool choice — and both options cost $9/month.
Does Zamzar preserve VBA macros? No. Zamzar's XLSM conversion produces a correctly-rendered output file, but VBA macro code is stripped during the conversion process. This applies to all output formats including XLSX. Zamzar does not document this limitation in its conversion guides.
Can I use Zamzar for Excel files that have no macros? Yes. For XLSX, XLS, and CSV files without VBA, Zamzar produces correct output and is a reliable, well-priced option. The macro stripping issue is specific to XLSM, XLSB, XLAM, DOCM, and PPTM formats.
What does Macro-Safe Converter membership include? The $9/month membership covers unlimited conversions, full VBA extraction packaged with every output, batch upload, API access, and monthly niche research drops — keyword data, competitive intelligence, and format support updates for file-conversion SaaS builders. Join the membership →
Is Zamzar good for high-volume conversion? Yes, for general file formats. Zamzar's Pro ($18/month) and Business ($27/month) plans cover higher volumes. If your high-volume workload involves macro-containing Excel files, Macro-Safe Converter's unlimited membership is more cost-effective at $9/month.
How old is Zamzar? Zamzar launched in 2006 and is one of the longest-running file conversion services. Its longevity is a trust signal for general-purpose conversion. However, its architecture pre-dates the modern Excel macro ecosystem and has not been updated to support VBA preservation.
Zamzar is a reliable, well-priced converter with a legitimate track record across 1,200+ formats. For anything that isn't a macro-containing Excel file, it is a perfectly reasonable choice.
For XLSM, XLAM, DOCM, and XLSB — the formats where your automation code lives — Zamzar will convert the file and discard the macros. There is no configuration option to change this.
Macro-Safe Converter solves the specific problem that Zamzar cannot: your VBA code travels with the output, every time.
Start with the $9/month membership — protect your Excel macros →
See how macro loss plays out in practice — and what recovery actually looks like:
Schema: SoftwareApplication comparison, Review, FAQPage
Macro-Safe Converter preserves VBA macros through XLSM conversions. One-time kit — no subscription.
Get the Kit — $9 one-time →