Amazon Flat File Validator

This Amazon flat file validator checks an Amazon inventory file template — the tab-delimited spreadsheet you upload through Seller Central — for the structural and field-level problems that trigger listing errors before you ever submit it. Paste or upload your file and see which rows and columns break the rules every category template shares, in plain language, so a CPG, furniture, or MRO catalog onboards cleanly the first time.

Amazon Flat File Validator

Runs in your browser · no upload

Upload the flat file (.txt, tab-delimited), or paste the rows straight from Excel

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File checks

Rows with findings

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Checks the rules shared by every category template. Category-specific required attributes and valid-value lists are only in the template you download from Seller Central, so check those against its Data Definitions and Valid Values tabs. See how Claro builds clean channel feeds from one product record →

What it checks

The validator checks the rules that are the same in every category template, instantly and before submission:

• Template structure — confirms the three header rows (the TemplateType signature line, the human-readable labels, and the machine field names like feed_product_type, item_sku, external_product_id) are present and in the right order.
• Required fields — flags rows missing the values every listing needs: item_sku, external_product_id and its type, brand_name, item_name, and feed_product_type. PartialUpdate and Delete rows are checked only for what they carry.
• Parent/child variations — parent rows need a variation_theme and no product ID; child rows need a parent_sku that exists, relationship_type Variation, and the parent’s theme.
• Identifier validity — runs UPC, EAN, and GTIN values through check-digit math and length rules, and confirms external_product_id_type matches the value supplied (a 12-digit UPC tagged as an EAN, for example).
• SKU and title limits — SKUs over 40 characters, titles over 200 characters (or over 75, the cap Amazon applies outside media since July 2026), characters Amazon bans in titles, and words repeated more than twice.
• Numeric and format rules — catches non-numeric prices, decimal commas, negative or fractional quantities, currency codes that are not ISO, and dates not in YYYY-MM-DD form.
• Duplicate SKUs — surfaces repeated item_sku values that would collide on upload.
• Encoding and delimiter integrity — detects stray tabs, broken UTF-8 characters, and quoting that shifts columns out of alignment.

How the Amazon flat file validator works

Amazon flat files are tab-delimited text exported from the category-specific inventory template you download in Seller Central. Each template carries its own required-field set keyed off feed_product_type, so a category like industrial fasteners demands different attributes than home furniture or packaged food. The validator parses the three-row header block, maps your columns to Amazon’s machine field names, then evaluates every data row against the rules all templates share: required presence, identifier check digits, variation links, length limits, and numeric formats. Category-specific required attributes and valid-value lists ship only inside each template, so the tool leaves those to the template’s Data Definitions and Valid Values tabs.

Identifier checks use the published GS1 standards — UPC-A and EAN-13 check-digit algorithms and GTIN length rules — rather than guessing, so a transposed digit in a barcode is caught deterministically.

The tool reports problems, it does not invent data. Where a value is missing or malformed it tells you the row, the field, and the rule it failed, leaving the fix to you or to an automated enrichment step.

Related resources

FAQ

What is an Amazon flat file? +

An Amazon flat file is a category-specific, tab-delimited spreadsheet template you download in Seller Central and use to add or update many listings at once. It carries a header block that identifies the template type and the required fields for that product category, then one row per SKU.

Why does my Amazon flat file keep getting errors? +

The most common causes are a missing feed_product_type, absent required fields like item_sku or external_product_id, an identifier whose check digit or product_id_type does not match, broken parent/child variation links, values that fall outside Amazon’s accepted list for a field, or encoding and delimiter damage that shifts your columns. This validator flags all of those except the category-specific valid-value lists, which you check against your template’s Valid Values tab.

Do I need to upload my file anywhere to validate it? +

No. The validator runs entirely in your browser. Your inventory file is parsed locally and never sent to a server, so there is no login and no file-size cap beyond your own device’s memory.

Will this fix the errors for me? +

It diagnoses rather than rewrites: you get the exact row, field, and failed rule for every issue, but the corrections stay under your control. For large or recurring catalogs, an automated matching and enrichment layer can resolve the underlying records so clean files are generated rather than patched by hand.

Does it work for any Amazon category? +

It works on any category’s flat file, but it checks only the rules every template shares: the header block, SKU, title, brand, product type, product IDs, variations, number formats, and encoding. Each category’s own required attributes and valid values live in the template you download from Seller Central, so check those against its Data Definitions and Valid Values tabs.