Identifier Converter
Bulk-convert between ASIN (Amazon Standard Identification Number), UPC, EAN, and ISBN identifiers across Amazon marketplaces. Paste a list or upload a file and download the mapped results.
Open this page in your dashboard: Go to Identifier Converter →
📋 Overview
A supplier sends you a wholesale list of 200 products, each one identified only by its UPC. To evaluate any of them you need the matching ASINs so you can pull them up on Amazon, but hand-searching 200 barcodes one at a time is a lost afternoon. The Identifier Converter turns that list into ASINs in a single pass.
The Converter is a bulk-conversion tool built into the Sourcer page. It lets you convert between Amazon product identifiers. ASIN, UPC, EAN, and ISBN, in large batches. Whether you have a supplier spreadsheet full of EAN codes and need the matching ASINs for a specific marketplace, or you need to reverse-lookup UPCs from a list of ASINs, the Converter handles it in seconds.
Accessing the Converter
Log in to your SellerMagnet dashboard.
Navigate to Sourcer in the left menu.
Click the Converter tab at the top of the page.
Input Methods
The Converter accepts identifiers through two channels, displayed side by side:
Text Input
Input field
Multi-line textarea with monospace font
Accepted formats
One identifier per line
Accepted types
ASIN, UPC, EAN, ISBN-10, ISBN-13
Max per batch
Up to 50 identifiers per conversion (extra lines are ignored)
Paste your list directly. Each line should contain a single identifier. The system auto-detects the identifier type.
File Upload
Drop zone
Drag-and-drop area or click to browse
Accepted formats
.csv, .xlsx, .xls
Column detection
Automatically identifies the column containing identifiers
Pro tip: When using a CSV file, ensure the identifier column has a clear header like "ASIN", "EAN", or "UPC". This helps the auto-detection work reliably even in multi-column files.
Running a Conversion
Paste identifiers into the text field or upload a file.
Click the Convert button.
A progress indicator shows the conversion status.
Results appear in a table below the input section.
Results Table
The results table displays one row per input identifier:
Input
The original identifier you provided
Type
Auto-detected identifier type, shown as a colored badge (ASIN, EAN, UPC, or ISBN)
ASIN
Amazon Standard Identification Number (links to the Amazon listing)
EAN
European Article Number(s) mapped to the ASIN
Title
Listing title. Always shown, and the cell is editable so you can tidy a label before exporting
Status
Success or Failed
Statistics Bar
Above the results, a statistics bar summarizes:
Total input
Number of identifiers submitted
Converted
Successfully converted identifiers
Failed
Identifiers with no matching Amazon catalog entry
📤 Exporting Results
The Export button is a split menu. Pick CSV or Excel to download the results, including every column from the table, ready to import into your inventory management system, supplier negotiation spreadsheet, or listing tool.
🚀 Analyze in Bulk Sourcer
Next to Export, an Analyze in Bulk Sourcer button hands the converted ASINs straight to the Bulk Sourcer so you can run the full profitability analysis over them in one job, no re-typing. It opens the Bulk Sourcer pre-loaded with the ASINs the conversion resolved (/tools/bulk-sourcer?source=converter&asins=...). Duplicate and unresolved rows are dropped automatically, so only the clean, unique ASINs are carried over.
🎯 Realistic Example
Scenario: You receive a wholesale price list from a European distributor with EAN codes (with your project's default marketplace set to Amazon.de). You need to find the matching ASINs to evaluate profitability.
Open the Converter tab.
Copy the EAN codes from the spreadsheet and paste them into the text area (up to 50 per batch).
Click Convert.
In a few seconds, the results table populates. Most EANs match an ASIN; a handful return "Failed" (meaning the product is not yet listed on your default marketplace).
Click Analyze in Bulk Sourcer to push the matched ASINs into the Bulk Sourcer for a full profitability run, or Export the results as CSV or Excel and paste the ASINs into the Sourcer's Overview tab one at a time.
## ✅ Best Practices
Deduplicate your list before uploading: Remove duplicate identifiers to speed up conversion and avoid wasted lookups.
Mind your default marketplace: Identifier mappings are marketplace-specific. A UPC may map to different ASINs on Amazon.com vs. Amazon.de, so set your project's default marketplace to the region the codes belong to before converting.
Combine with the Sourcer: After converting, use Analyze in Bulk Sourcer to score the whole batch at once, or paste matched ASINs into the Sourcer's Overview search to analyze them individually.
Save exports for future reference: Keep converted files organized by supplier and date for easy re-evaluation when prices change.
Handle "Failed" results: Products with no ASIN match may represent listing opportunities. Consider creating a new listing for those EANs.
🔧 Troubleshooting
If a conversion does not behave as expected, work through the situations below before re-running the batch.
Mixed-identifier batches
The Converter auto-detects the type of each line, so a batch that mixes ASINs, EANs, and UPCs is allowed. The risk is misclassification: a bare 12- or 13-digit number can look like more than one code type, and a value with a stripped leading zero can be read as the wrong length. If some rows come back with an unexpected type or a "Not Found" you cannot explain, split the list so each batch holds one identifier type, or upload a file where the identifier column carries a clear header ("ASIN", "EAN", "UPC") so detection has a hint. Keeping types separate also makes the results table easier to read.
Partial file-parse failures
When a file uploads but only some rows convert, the parser usually skipped cells it could not read cleanly. The common causes are merged cells, the identifier column not being detected (missing or ambiguous header), stray text or notes in the identifier column, and blank lines. Flatten any merged cells, give the identifier column a single clear header, remove non-identifier text from that column, and re-upload. If a spreadsheet keeps failing, export it to .csv first. CSV is the most predictable format for the parser.
Identifiers that will not resolve on your default marketplace
A code that is valid but returns "Failed" is almost always a marketplace mismatch, not a bad identifier. Amazon catalog entries and their identifier mappings are marketplace-specific, so a UPC that resolves on Amazon.com may have no entry on Amazon.de, and the same product can carry different ASINs per region. Lookups run against your project's default marketplace (Amazon.com if none is set), so confirm that default matches where the products are actually listed, then re-run. If the item genuinely is not listed on that marketplace, the "Failed" is correct. Treat those rows as listing opportunities rather than errors. Also re-check for typos and stripped leading zeros before assuming the catalog is at fault.
File format issues
Uploads must be .csv, .xlsx, or .xls. A file that is rejected on upload is usually the wrong extension (for example, .txt or .numbers). Re-save in a supported format, and remove unused columns and extra sheets so only the identifier data remains. Remember the per-batch cap as well: only the first 50 identifiers in any input are processed, so a large file will convert its first 50 rows and ignore the rest. Split long lists into batches of 50 and run them in sequence.
❓ FAQ
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