Open product methodology

Know exactly what the result means.

FeedGuardrail exposes its release identity, deterministic rule coverage, processing boundaries, and evidence format so a result can be inspected instead of taken on faith.

Processing model

From file to actionable report

Read locally

Your selected feed is read in browser memory. The file is not sent to FeedGuardrail.

Normalize safely

Headers and supported CSV, TSV, RSS/XML, and Atom/XML records are converted into a consistent local model.

Run versioned rules

The google-merchant-online-product-data-2026-09-09.1 ruleset evaluates product rows and cross-feed relationships deterministically.

Test declared intent

Actual changed fields and product counts are compared with the portable change contract selected for the release.

Gate and export

The contract and safety policy decide pass, review, or block; separate evidence and operator-ledger exports preserve the decision and normalized field changes.

Supported inputs: CSV, TSV, RSS/XML, Atom/XML · up to 100,000 product rows, 500 columns, and 25 MB per selected file. A desktop-class device is recommended for large catalogs; practical capacity varies with file width, browser, and available memory.

Ruleset scope: general online product data, evaluated from selected file contents. It is not Google’s Local Inventory specification and cannot infer program enrollment, target country, product category, or account state. The Vehicle ads value build_to_order receives a contextual review warning rather than a false unsupported-value error.

Intent and safety controls as data

A decision you can inspect, edit, save, and rerun.

FeedGuardrail 1.3.0 separates what the release is intended to change from what must remain safe. Both controls can be edited or loaded as strict JSON, then travel with evidence format v3 so another person can rerun the exact decision.

Strict production

Zero removals, large price changes, warnings, or in-stock drops.

Balanced operations

Small bounded changes are allowed; material integrity risks still block.

Observe broad changes

Wider planned refreshes are allowed while core blockers stay active.

Declared change contract

Content correction, price or promotion, availability sync, and broad-refresh profiles define allowed fields and maximum changed, added, and removed products. A contract can name every supported feed column—up to 500 fields—or use * alone for a genuinely unrestricted refresh. Unexpected scope can require review or block the release even when every changed value is individually valid.

Always blocking: candidate errors, introduced errors, required-value blanking, currency changes, likely product-ID churn, and removed required headers. Policy thresholds then govern removals, large price moves, warning volume, availability drops, and overall change breadth.

Rule catalog

49 sourced deterministic checks

Every rule names its platform basis, local detection coverage, applicability, primary source, and known limitation. This separates Google’s published requirements from FeedGuardrail’s operational judgment.

Sources reviewed 2026-09-09

required-id

Missing product ID

errorGoogle requirementDirect local check

Field and scope: id · product row
Applies when: Every in-scope online product.
Local detector: Products without a stable identifier.

Primary source:G-ID · ID [id]

id-limit

Product ID exceeds 50 characters

errorGoogle format constraintDirect local check

Field and scope: id · product row
Applies when: Every submitted id.
Local detector: Product identifiers beyond Google’s supported length.

Primary source:G-ID · ID [id]

id-characters

Product ID contains unsupported characters

errorGoogle requirementPartial local coverage

Field and scope: id · product row
Applies when: Every submitted id.
Local detector: Unicode control, format, private-use, surrogate, or unassigned characters that can make product identity unstable.
Known limitation: Local Unicode-category screening cannot prove how every downstream source normalizes or preserves the identifier.

Primary source:G-ID · ID [id]

required-title

Missing title

errorGoogle requirementPartial local coverage

Field and scope: title / structured_title · product row
Applies when: Every product; either title or structured_title satisfies presence.
Local detector: Products without either a plain or structured title.
Known limitation: Structured-title subattributes and digital-source declarations are not semantically validated.

Primary sources:G-TITLE · Title [title] and structured title [structured_title]G-PDS · Product data specification

title-limit

Title exceeds 150 characters

warningGoogle format constraintPartial local coverage

Field and scope: title · product row
Applies when: A plain title is submitted.
Local detector: Plain titles beyond the supported length.
Known limitation: Structured-title content length is not independently parsed.

Primary source:G-TITLE · Title [title] and structured title [structured_title]

title-front-load

Title may hide important details

warningGoogle best practiceAdvisory proxy

Field and scope: title · product row
Applies when: A plain title exceeds 70 characters.
Local detector: Long titles whose useful attributes may be truncated in placements.
Known limitation: Length alone cannot establish whether decisive attributes are actually hidden.

Primary source:G-TITLE · Title [title] and structured title [structured_title]

title-editorial

Title may violate editorial guidance

warningGoogle requirementAdvisory proxy

Field and scope: title · product row
Applies when: A plain title is submitted.
Local detector: Heavy capitalization or a limited set of common promotional phrases.
Known limitation: The phrase list and capitalization ratio can miss violations or flag legitimate acronym-heavy titles.

Primary source:G-TITLE · Title [title] and structured title [structured_title]

required-description

Missing description

warningGoogle requirementPartial local coverage

Field and scope: description / structured_description · product row
Applies when: Every product; either description or structured_description satisfies presence.
Local detector: Products without either a plain or structured description.
Known limitation: The local warning reflects Google’s documented limited-performance consequence; structured subattributes are not semantically validated.

Primary sources:G-DESC · Description [description] and structured description [structured_description]G-PDS · Product data specification

description-limit

Description exceeds 5,000 characters

warningGoogle format constraintPartial local coverage

Field and scope: description · product row
Applies when: A plain description is submitted.
Local detector: Plain descriptions beyond the supported length.
Known limitation: Structured-description content is not independently parsed.

Primary source:G-DESC · Description [description] and structured description [structured_description]

required-link

Missing landing-page link

errorGoogle requirementDirect local check

Field and scope: link · product row
Applies when: Every product.
Local detector: Products without a destination URL.

Primary source:G-LINK · Link [link]

invalid-link

Invalid landing-page URL

errorGoogle requirementPartial local coverage

Field and scope: link · product row
Applies when: A link is submitted.
Local detector: Destination values that are not complete HTTP or HTTPS URLs.
Known limitation: A local parser cannot prove domain ownership, crawlability, redirect behavior, page usability, or product consistency.

Primary source:G-LINK · Link [link]

link-format-limit

Landing-page URL exceeds channel format limits

errorGoogle format constraintPartial local coverage

Field and scope: link · product row
Applies when: A link is submitted.
Local detector: Product links with non-ASCII URL characters or more than 2,000 characters.
Known limitation: ASCII and length are checked; raw RFC 3986 compliance and downstream normalization are not fully proven.

Primary source:G-LINK · Link [link]

required-image

Missing primary image link

errorGoogle requirementDirect local check

Field and scope: image_link · product row
Applies when: Every product.
Local detector: Products without a primary image URL.

Primary source:G-IMAGE · Image link [image_link]

invalid-image

Invalid image URL

errorGoogle requirementPartial local coverage

Field and scope: image_link · product row
Applies when: An image_link is submitted.
Local detector: Image values that are not complete HTTP or HTTPS URLs.
Known limitation: The target is not fetched, so media type, crawlability, stability, dimensions, and policy compliance remain unknown.

Primary source:G-IMAGE · Image link [image_link]

image-format-limit

Image URL exceeds channel format limits

errorGoogle format constraintPartial local coverage

Field and scope: image_link · product row
Applies when: An image_link is submitted.
Local detector: Primary image links with non-ASCII URL characters or more than 2,000 characters.
Known limitation: This is a local URL-envelope check only.

Primary source:G-IMAGE · Image link [image_link]

mobile-link-format

Invalid mobile landing-page URL

errorGoogle format constraintPartial local coverage

Field and scope: mobile_link · product row
Applies when: Optional mobile_link is present.
Local detector: Submitted mobile destinations outside the supported URL and length envelope.
Known limitation: The mobile page is not fetched or compared with the product.

Primary source:G-MOBILE · Mobile link [mobile_link]

additional-image-format

Invalid additional image list

errorGoogle format constraintPartial local coverage

Field and scope: additional_image_link · product row
Applies when: Optional additional_image_link is present.
Local detector: Malformed additional-image URLs or lists containing more than ten values.
Known limitation: URLs are checked locally; image contents, crawlability, and all repeated-field encoding cases are not proven.

Primary source:G-ADDIMAGE · Additional image link [additional_image_link]

video-link-format

Invalid product video URL list

errorGoogle format constraintPartial local coverage

Field and scope: video_link · product row
Applies when: Optional video_link is present.
Local detector: Malformed video URLs or lists containing more than ten values.
Known limitation: URLs and count are checked, but format, direct-file behavior, crawlability, duration, size, resolution, and aspect ratio are not.

Primary source:G-VIDEO · Video link [video_link]

availability-enum

Missing or unsupported availability

errorGoogle requirementPartial local coverage

Field and scope: availability · product row
Applies when: Standard online products.
Local detector: Standard online-product availability outside the documented vocabulary.
Known limitation: Product-program context is not inferred; Vehicle ads build_to_order is handled as a separate review warning.

Primary source:G-AVAIL · Availability [availability]

vehicle-availability-context

Vehicle-only availability needs review

warningConditional Google requirementAdvisory proxy

Field and scope: availability · product row
Applies when: availability is build_to_order.
Local detector: build_to_order values whose Vehicle ads context cannot be established locally.
Known limitation: The file alone cannot establish enrollment in or eligibility for Vehicle ads.

Primary source:G-AVAIL · Availability [availability]

availability-date-required

Missing availability date

errorConditional Google requirementDirect local check

Field and scope: availability_date · product row
Applies when: availability is preorder or backorder.
Local detector: Preorder or backorder products without an availability date.

Primary sources:G-AVAIL · Availability [availability]G-AVAILDATE · Availability date [availability_date]

availability-date-format

Invalid availability date

errorGoogle format constraintPartial local coverage

Field and scope: availability_date · product row
Applies when: availability_date is present.
Local detector: Availability dates outside the supported ISO 8601 envelope.
Known limitation: Syntax is checked, but landing-page visibility and the maximum future horizon are not.

Primary sources:G-AVAILDATE · Availability date [availability_date]G-DATE · Format date and time

price-format

Missing or invalid price

errorGoogle requirementPartial local coverage

Field and scope: price · product row
Applies when: Every product.
Local detector: Prices without a non-negative number and recognized ISO 4217 currency code.
Known limitation: Syntax and a versioned recognized-currency set are checked; target-country support, page equality, checkout equality, and program context are not.

Primary sources:G-PRICE · Price [price]G-CURRENCY · Supported languages and currencies

price-rounding

Price precision will be rounded

warningGoogle format constraintDirect local check

Field and scope: price / sale_price · product row
Applies when: price or sale_price has more than two decimal places.
Local detector: Price values carrying more than two decimal places.
Known limitation: FeedGuardrail warns before Google’s documented rounding; it does not predict the displayed rounded value in every currency context.

Primary sources:G-PRICE · Price [price]G-SALE · Sale price [sale_price]

zero-price-context

Zero price needs program review

warningConditional Google requirementAdvisory proxy

Field and scope: price / sale_price · product row
Applies when: price or sale_price equals zero.
Local detector: Zero prices whose documented contract or subscription exception cannot be established locally.
Known limitation: The local file cannot establish a qualifying device-contract or physical-subscription program.

Primary sources:G-PRICE · Price [price]G-SALE · Sale price [sale_price]

sale-price

Invalid sale price

errorConditional Google requirementPartial local coverage

Field and scope: sale_price · product row
Applies when: Optional sale_price is present.
Local detector: Sale prices with invalid syntax, mismatched currency, or an amount not below regular price.
Known limitation: The local check cannot prove promotion timing, landing-page display, checkout price, or program-specific zero-price eligibility.

Primary sources:G-SALE · Sale price [sale_price]G-PRICE · Price [price]

sale-date-format

Invalid sale price effective date

errorGoogle format constraintPartial local coverage

Field and scope: sale_price_effective_date · product row
Applies when: Optional sale_price_effective_date is present.
Local detector: Sale windows without two ordered ISO 8601 dates or date-times.
Known limitation: The ordered ISO envelope is checked; promotion eligibility and live behavior are not.

Primary sources:G-SALEDATE · Sale price effective date [sale_price_effective_date]G-DATE · Format date and time

expiration-date-format

Invalid expiration date

errorGoogle format constraintPartial local coverage

Field and scope: expiration_date · product row
Applies when: Optional expiration_date is present.
Local detector: Expiration values outside supported ISO 8601 date formats.
Known limitation: Syntax is checked; the maximum future horizon is not evaluated to preserve rerun determinism.

Primary sources:G-EXPIRY · Expiration date [expiration_date]G-DATE · Format date and time

condition-enum

Unsupported condition

errorGoogle format constraintPartial local coverage

Field and scope: condition · product row
Applies when: condition is supplied; it is contextually required for used or refurbished products.
Local detector: Submitted conditions outside the general online-product vocabulary.
Known limitation: Missing condition and Vehicle-ad-specific context cannot be inferred from arbitrary feeds.

Primary source:G-CONDITION · Condition [condition]

adult-boolean

Invalid adult-content flag

errorGoogle format constraintPartial local coverage

Field and scope: adult · product row
Applies when: adult is supplied.
Local detector: Adult flags outside yes, true, no, or false.
Known limitation: The tool cannot determine whether an unlabeled product contains adult content.

Primary source:G-ADULT · Adult [adult]

bundle-boolean

Invalid bundle flag

errorGoogle format constraintPartial local coverage

Field and scope: is_bundle · product row
Applies when: is_bundle is supplied.
Local detector: Bundle flags outside yes, true, no, or false.
Known limitation: The tool cannot determine whether an unlabeled offer is a merchant-defined bundle.

Primary source:G-BUNDLE · Bundle [is_bundle]

multipack-format

Invalid multipack quantity

errorConditional Google requirementPartial local coverage

Field and scope: multipack · product row
Applies when: multipack is supplied for a retailer-defined multipack.
Local detector: Multipack quantities that are not positive whole numbers.
Known limitation: The tool cannot distinguish retailer-defined from manufacturer-defined packs or detect every missing attribute.

Primary source:G-MULTIPACK · Multipack [multipack]

age-group-enum

Unsupported age group

errorConditional Google requirementDirect local check

Field and scope: age_group · product row
Applies when: age_group is supplied; requiredness varies by product and target country.
Local detector: Submitted age-group values outside Google’s vocabulary.

Primary source:G-AGE · Age group [age_group]

gender-enum

Unsupported gender value

errorConditional Google requirementDirect local check

Field and scope: gender · product row
Applies when: gender is supplied; requiredness varies by product and target country.
Local detector: Submitted gender values outside Google’s vocabulary.

Primary source:G-GENDER · Gender [gender]

size-system-enum

Unsupported size system

warningGoogle format constraintDirect local check

Field and scope: size_system · product row
Applies when: Optional apparel size_system is supplied.
Local detector: Submitted size systems outside Google’s country and region codes.

Primary source:G-SIZESYSTEM · Size system [size_system]

size-type-enum

Unsupported size type

warningGoogle format constraintDirect local check

Field and scope: size_type · product row
Applies when: Optional apparel size_type is supplied.
Local detector: Size-type values or repetitions outside Google’s vocabulary.

Primary source:G-SIZETYPE · Size type [size_type]

product-type-limit

Product type exceeds repetition or length limits

warningGoogle format constraintPartial local coverage

Field and scope: product_type · product row
Applies when: Optional product_type is supplied.
Local detector: More than five merchant hierarchies or any hierarchy beyond 750 characters.
Known limitation: Common comma-separated repetitions are checked; every possible quoted repeated-field encoding is not reconstructed.

Primary source:G-PRODUCTTYPE · Product type [product_type]

custom-label-limit

Custom label exceeds 100 characters

warningGoogle format constraintPartial local coverage

Field and scope: custom_label_0 … custom_label_4 · product row
Applies when: A custom_label_0 through custom_label_4 value is supplied.
Local detector: Campaign-segmentation labels beyond the supported length.
Known limitation: The account-wide unique-value limit cannot be established from one selected file.

Primary source:G-CUSTOMLABEL · Custom label 0–4 [custom_label_0–4]

shipping-weight-format

Invalid shipping weight

errorGoogle format constraintPartial local coverage

Field and scope: shipping_weight · product row
Applies when: Optional shipping_weight is supplied.
Local detector: Shipping weights outside documented units or upper bounds.
Known limitation: Syntax and published upper bounds are checked; carrier configuration and contextual requiredness are not.

Primary source:G-SHIPWEIGHT · Shipping weight [shipping_weight]

identifier-boolean

Unrecognized identifier_exists value

warningGoogle format constraintDirect local check

Field and scope: identifier_exists · product row
Applies when: Optional identifier_exists is supplied.
Local detector: Identifier flags outside yes, true, no, or false.

Primary source:G-IDEXISTS · Identifier exists [identifier_exists]

identifier-incomplete

Product identifiers look incomplete

warningFeedGuardrail guardrailAdvisory proxy

Field and scope: gtin / brand / mpn · product row
Applies when: The product is not explicitly marked as having no assigned identifiers.
Local detector: Products that may be missing the identifier combination expected for their context.
Known limitation: Expected combinations depend on category, condition, manufacturer status, and whether identifiers were assigned.

Primary sources:G-UPI · About unique product identifiers G-IDEXISTS · Identifier exists [identifier_exists]G-GTIN · GTIN [gtin]G-PDS · Product data specification

invalid-gtin

Malformed GTIN

errorGoogle format constraintPartial local coverage

Field and scope: gtin · product row
Applies when: One or more GTIN values are supplied.
Local detector: GTINs with an unsupported length or failed check digit.
Known limitation: Length and check digit are checked; restricted prefixes, coupon ranges, allocation status, and packaging-level restrictions are not.

Primary sources:G-GTIN · GTIN [gtin]G-UPI · About unique product identifiers

duplicate-id

Duplicate product ID

errorGoogle requirementPartial local coverage

Field and scope: id · whole feed
Applies when: Distinct rows in the selected file.
Local detector: A product ID used by more than one row in the selected file.
Known limitation: Uniqueness across other active sources and historical ID reuse are outside a local-file check.

Primary source:G-ID · ID [id]

case-variant-id

Product IDs differ only by casing

warningGoogle requirementDirect local check

Field and scope: id · whole feed
Applies when: IDs in the selected file differ only by casing.
Local detector: IDs that become ambiguous when case is ignored.

Primary source:G-ID · ID [id]

mixed-currency

Multiple currencies in one feed

warningFeedGuardrail guardrailAdvisory proxy

Field and scope: price · whole feed
Applies when: The selected file contains more than one parsed currency.
Local detector: Catalogs that may contain accidentally combined regional prices.
Known limitation: Google does not prohibit every mixed-currency feed; legitimate multi-country and conversion workflows exist.

Primary sources:G-CURRENCY · Supported languages and currencies G-MULTICOUNTRY · Shopping ads and free listings in multiple countries G-PRICE · Price [price]

single-variant-group

Variant group contains one product

warningFeedGuardrail guardrailAdvisory proxy

Field and scope: item_group_id · whole feed
Applies when: An item_group_id appears once in the selected file.
Local detector: A group represented by only one row in the selected file.
Known limitation: Sibling variants may be inactive, filtered, or supplied through another source.

Primary source:G-ITEMGROUP · Item group ID [item_group_id]

item-group-limit

Item group ID exceeds 50 characters

errorGoogle format constraintDirect local check

Field and scope: item_group_id · product row
Applies when: item_group_id is supplied.
Local detector: Variant-group identifiers beyond the supported length.

Primary source:G-ITEMGROUP · Item group ID [item_group_id]

item-group-self

Product ID equals item group ID

warningGoogle best practiceAdvisory proxy

Field and scope: id / item_group_id · product row
Applies when: id equals item_group_id.
Local detector: A child offer identifier reused as its shared group identifier.
Known limitation: Equality is a strong semantic warning, not a separately documented syntax rejection.

Primary source:G-ITEMGROUP · Item group ID [item_group_id]

duplicate-variant

Duplicate variant attributes

warningGoogle requirementPartial local coverage

Field and scope: item_group_id / color / size / material / pattern / age_group / gender / variant_option · whole feed
Applies when: Multiple rows share item_group_id and populated standard or structured variant dimensions.
Local detector: Products in one group that share the same populated standard or structured variant dimensions.
Known limitation: The signature covers color, size, material, pattern, age_group, gender, and raw variant_option; it cannot prove every custom dimension or landing-page choice.

Primary sources:G-DUPVARIANT · How to fix: Duplicate variant G-ITEMGROUP · Item group ID [item_group_id]G-VARIANTOPTION · Variant option [variant_option]

Reproducible evidence

A comparison record another person can rerun.

Release Gate evidence v3 records the exact input-file SHA-256 hashes, declared change contract, ruleset, safety policy, pass/review/block checks, issue outcomes, field drift, price and availability movement, identity risk, and inventory/schema changes. A recipient can load that evidence with both exact files and reproduce the decision locally.

Exact inputs

Two SHA-256 hashes bind the record to the baseline and candidate file bytes.

Stable decision logic

The evidence names the versioned ruleset and embeds the exact validated change contract and safety policy.

Privacy minimized

Filenames and product IDs are excluded by default; no feed rows or raw row-level values are embedded.

Unsigned evidence: hashes prove a byte-for-byte match to recorded inputs, and the local rerun checks reproducibility. The versioned evidence-v3 HTML is checked against its canonical embedded record, but the pack is not a digital signature, certification, authorship proof, proof of prior authorization, proof that it is the original export, or guarantee of Google approval. Its timestamp and optional filename labels are self-reported metadata. Someone holding both feeds can generate a different internally consistent pack with different controls.

Separate operator change ledger

A local CSV lists normalized before/after values for uniquely matched product-field changes, product membership changes, and explicit comparison-ambiguity records with critical, review, or informational risk. It is spreadsheet-formula protected and deliberately separate from privacy-minimized shareable evidence.

Primary specification sources

Each rule above links directly to the official Google page used for its classification and records the review date. Google can change its specifications; a dated source review is stronger than an unsourced claim but does not make FeedGuardrail affiliated with Google or guarantee channel approval. FeedGuardrail’s release contracts and safety thresholds remain its own operational controls.

Honest boundaries

What local checks cannot prove

Landing-page price or availability parity
Live image crawlability or image-content policy
Merchant Center account, policy, or diagnostics state
Approval, traffic, revenue, or advertising performance

Inspect it, then use it.

Run the built-in samples before selecting a real feed. No account or ad-platform connection is required.

Evaluate a release