> For the complete documentation index, see [llms.txt](https://docs.sellermagnet.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sellermagnet.com/selling-tools/product-sourcer-overview/identifier-converter.md).
# Identifier Converter
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**Difficulty:** ๐ก Intermediate ยท **Reading time:** \~7 min
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**Open this page in your dashboard:** [**Go to Identifier Converter โ**](https://dashboard.sellermagnet.com/sourcer/converter)
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## ๐ 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
1. Log in to your SellerMagnet dashboard.
2. Navigate to **Sourcer** in the left menu.
3. 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
| Feature | Details |
| -------------------- | ------------------------------------------------------------- |
| **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
| Feature | Details |
| -------------------- | ---------------------------------------------------------- |
| **Drop zone** | Drag-and-drop area or click to browse |
| **Accepted formats** | `.csv`, `.txt`, `.xlsx` |
| **Max file size** | 5 MB |
| **Column detection** | Automatically identifies the column containing identifiers |
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**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.
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***
## Configuration Options
Before running the conversion, configure the following:
| Setting | Description |
| ------------------------ | ------------------------------------------------------- |
| **Target marketplace** | The Amazon marketplace to look up identifiers against |
| **Output format** | Choose which identifier types to include in the results |
| **Include product info** | Optionally enrich results with product title and image |
### Choosing an output format
The output format controls which identifier columns come back in the results table and the export. Because every lookup already resolves an item to its Amazon catalog entry, the format is about what you keep, not about how hard the tool works.
* **All identifiers (default):** Returns ASIN, EAN, UPC, and ISBN side by side for each input. Pick this when you are not sure which codes you will need downstream, or when you want a single reference file that maps every identifier type at once. It produces the widest export.
* **A single target type (for example, ASIN only):** Returns just the identifier you plan to act on and drops the rest. Use this when the next step only needs one code. Converting a supplier's EAN list into ASINs to paste into the Sourcer Overview is the classic case. A narrower output keeps the export clean and avoids empty columns for types that do not apply (for example, ISBN on non-book products).
If you are unsure, leave the default. You can always re-run a batch with a narrower format later, and trimming columns in the exported CSV is trivial.
### When to include product info
**Include product info** is a toggle. Turn it on to also return the product title (and image where shown) alongside the converted identifier, so you can eyeball whether each match is the item you expected instead of trusting the code blindly. Turn it off to get back only the identifiers.
* **Toggle on** when you are reviewing an unfamiliar supplier list and want a human-readable label next to each row to catch mismatches, or when the export feeds a spreadsheet where a title column is useful for negotiation or listing work.
* **Toggle off** when you only need the raw mapped codes for a downstream tool, or when you want the leanest, fastest result. Enrichment pulls extra catalog fields for every row, so a plain identifier-only run is the lighter option for very large batches.
***
## Running a Conversion
1. Paste identifiers into the text field **or** upload a file.
2. Select the target Amazon marketplace from the dropdown.
3. Click the **Convert** button.
4. A progress indicator shows the conversion status.
5. Results appear in a table below the input section.
***
## Results Table
The results table displays one row per input identifier:
| Column | Description |
| ----------------- | ----------------------------------------------------- |
| **Input ID** | The original identifier you provided |
| **ASIN** | Amazon Standard Identification Number |
| **EAN** | European Article Number (13 digits) |
| **UPC** | Universal Product Code (12 digits) |
| **ISBN** | International Standard Book Number (when applicable) |
| **Status** | Success, Not Found, or Error |
| **Product Title** | Listing title (if product info enrichment is enabled) |
***
## Statistics Bar
Above the results, a statistics bar summarizes:
| Stat | Description |
| --------------- | ------------------------------------------------- |
| **Total input** | Number of identifiers submitted |
| **Matched** | Successfully converted identifiers |
| **Not found** | Identifiers with no matching Amazon catalog entry |
***
## ๐ค Exporting Results
Click the **Export** button to download results as a CSV file. The export includes all columns from the results table, making it easy to import into your inventory management system, supplier negotiation spreadsheet, or listing tool.
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**Tip:** The exported CSV uses UTF-8 encoding, which preserves special characters in product titles across all languages and marketplaces.
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***
## ๐ฏ Realistic Example
**Scenario:** You receive a wholesale price list from a European distributor with 200 EAN codes. You need to find the matching ASINs on Amazon.de to evaluate profitability.
1. Open the **Converter** tab.
2. Copy all 200 EAN codes from the spreadsheet and paste them into the text area.
3. Select **Amazon.de** as the target marketplace.
4. Click **Convert**.
5. In about 15 seconds, the results table populates. 187 EANs match an ASIN, 13 return "Not Found" (meaning the product is not yet listed on Amazon.de).
6. Export the CSV and import the matched ASINs into the Sourcer's **Overview** tab to run profitability analysis on each one.
***
โ ๏ธ Common Mistakes to Avoid
| Mistake | Why It Hurts |
| ------------------------------------------------------------- | ------------------------------------------------------------------ |
| Mixing multiple identifier types in one batch without headers | The auto-detection may misclassify some identifiers |
| Uploading a file with merged cells | Parsing fails on merged-cell spreadsheets; flatten them first |
| Forgetting to select the correct marketplace | ASIN-to-EAN mappings vary by marketplace; always match your target |
| Including leading zeros in a text file opened in Excel | Excel strips leading zeros from UPC/EAN numbers, use `.csv` format |
| Submitting duplicates | Wastes processing time; deduplicate your list before converting |
\## โ
Best Practices
1. **Deduplicate your list before uploading:** Remove duplicate identifiers to speed up conversion and avoid wasted lookups.
2. **Use the correct marketplace:** Identifier mappings are marketplace-specific. A UPC may map to different ASINs on Amazon.com vs. Amazon.de.
3. **Combine with the Sourcer Overview:** After converting, paste matched ASINs into the Sourcer's search to run full profitability analysis.
4. **Save exports for future reference:** Keep converted files organized by supplier and date for easy re-evaluation when prices change.
5. **Handle "Not Found" results:** Products with no ASIN match may represent listing opportunities. Consider creating a new listing for those EANs.
***
## ๐ง 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 the chosen marketplace
A code that is valid but returns "Not Found" 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. Confirm the **Target marketplace** matches where the products are actually listed, then re-run. If the item genuinely is not listed on that marketplace, the "Not Found" 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 and size limits
Uploads must be `.csv`, `.txt`, or `.xlsx` and no larger than 5 MB. A file that is rejected on upload is usually the wrong extension (for example, `.xls` or `.numbers`) or over the size cap. Re-save in a supported format, and if the file is large, 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.
***
## โ FAQ
How many identifiers can I convert at once?
Up to 50 identifiers per conversion. If you paste or upload more, only the first 50 are processed. Split larger lists into batches of 50 and run them in sequence.
Does the converter work across all Amazon marketplaces?
Yes. Select any marketplace connected to your Seller Central account. The converter queries Amazon's catalog for that specific marketplace.
Why do some identifiers return "Not Found"?
"Not Found" means the identifier has no matching Amazon catalog entry on the selected marketplace. Common reasons: the product is new or not yet listed, it was delisted, or it exists only on a different regional marketplace. Verify by searching the identifier directly on Amazon; if it appears there, try the matching marketplace or re-check the identifier for typos.
Does each conversion consume search credits?
Converter lookups use a separate quota from standard Sourcer searches. Check your plan details for the exact allocation.
Can I convert ASINs to EANs (reverse lookup)?
Yes. The converter works bidirectionally. Enter ASINs and the results will include the mapped EAN, UPC, and ISBN where available.
What file formats are supported for upload?
CSV, TXT, and XLSX files up to 5 MB. Ensure identifiers are in a single column with a clear header row.
***
## โก๏ธ What's Next?
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[Product Sourcer](/selling-tools/product-sourcer-overview.md)
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[Chrome Extension](/selling-tools/product-sourcer-overview/chrome-extension.md)
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