Every Amazon ad campaign leaks some spend on searches that will never convert for your product. A kitchen cutting board ad showing for "cutting board game." A premium cookware campaign clicking through for "cheap pots." A pet supply ad triggering for the name of a competing brand you do not sell. These are not rare edge cases. They are what broad and phrase match types produce by design as they explore the query space.
Negative keywords are how you close those gaps. They tell Amazon which searches should never trigger your ads, so your budget stays focused on the queries that actually convert. Getting a clean negative keyword list in place is one of the fastest ways to lower ACoS on an existing campaign without touching bids, and one of the first things to do when setting up a new one.
Here is how to approach finding them and adding them correctly.
What negative keywords do
A negative keyword is a search term you explicitly exclude from your campaigns or ad groups. When a shopper's query contains a term you have added as a negative, your ad does not show for that search.
They work because Amazon's match types are intentionally broad. Phrase match covers your keyword plus any additional words before or after it. Broad match covers synonyms, related searches, and variations Amazon deems relevant. Both of these are useful for discovery, but they inevitably surface searches your product is not right for. Negative keywords are the filtering layer that removes the irrelevant ones from that discovery net.
Without negatives, campaigns accrue spend on searches that generate clicks but not orders. That spend raises ACoS. It also skews your performance data, because your campaign metrics are now a blend of converting and non-converting traffic that is harder to optimize against. Wasted spend is one of the main things a well-maintained negative keyword list controls.
The two negative match types
Amazon offers two negative match types, and the distinction matters.
Negative exact. This blocks your ad only when a shopper's search matches the exact phrase you entered, in the same order, with no additional words. If you add "competitor brand x" as a negative exact, your ad will not show for that search, but it may still show for "competitor brand x alternative" or "vs competitor brand x."
Negative phrase. This blocks your ad for any search that contains your term as a continuous phrase. Adding "free" as a negative phrase blocks searches like "free cutting board," "free cookware set," and any other query containing the word "free." Negative phrase is broader and more powerful, but also carries more risk of blocking searches you did not intend to exclude.
The default for most negative keywords from the search term report is negative exact. You are blocking a specific query that you observed spending without converting. Negative phrase is better reserved for categories you know with certainty are always irrelevant: free, cheap, DIY, kids (if you sell an adult product), or any term that represents a fundamentally different buyer intent from what your product serves.
Where to find negative keywords: the search term report
The search term report is your primary source. It shows you the actual queries shoppers used when your ad triggered, how many times your ad showed, how many clicks you got, and how many orders resulted. Reading this report well is one of the most important weekly habits in Amazon PPC management.
Here is the process for pulling negative keyword candidates:
Step 1: Pull the report. In Seller Central, go to Reports, then Advertising Reports, then Search Term Report. Set the date range to the last 7 to 14 days. Download as a CSV.
Step 2: Sort by spend, descending. You want to see the terms that have cost the most money at the top. Terms with high spend and zero conversions are the highest-priority negatives.
Step 3: Apply a spend threshold. Decide on a minimum spend level worth reviewing. For most accounts, any search term that has spent two to three times your target cost-per-click with zero orders is worth investigating. For a product with a $1.50 target CPC, that is $3 to $4.50 of spend with no conversions as a starting threshold.
Step 4: Evaluate each term. Ask two questions. First: is this search term relevant to my product? If a shopper typed this and landed on my listing, would they plausibly buy? Second: has this term produced any orders? If the answer to the first is no, add it as a negative. If the answer is yes but the ACoS is very high, check if it has converted in a longer time window before adding a negative.
Step 5: Add at the right level. Negatives can be added at the campaign level (applies across all ad groups in that campaign) or ad group level (applies only to that specific ad group). Campaign-level negatives are simpler to manage. Ad group-level negatives are more precise. Use ad group-level when the same keyword might be converting in one ad group but not another.
What to look for beyond spend-with-no-conversions
The spend threshold method catches the obvious cases. These additional patterns in the search term report are also worth reviewing:
Wrong product type searches. Your product is a solid wood cutting board. The search term report shows spend on "plastic cutting board," "glass cutting board," and "flexible cutting board." You may sell wood only. Those material-specific variants are candidates for negative phrase blocks if you are certain you do not carry them.
Competitor brand terms. If your brand is not the one being searched for, clicks from competitor brand searches tend to convert poorly. You can add specific competitor brand names as negative exact terms to stop spending on branded queries you are unlikely to win. Be deliberate with this. Some competitor brand terms do convert for comparable products, especially in comparison or alternative searches.
Wrong buyer intent signals. Searches containing "how to," "tutorial," "free," "DIY," "repair," or similar terms often indicate informational intent rather than purchase intent. These shoppers are researching, not buying. Negative phrase on these term categories is often worthwhile across entire accounts, particularly in product categories where DIY and informational content is abundant.
Wrong size, model, or configuration. If you sell a 12-inch skillet and the report shows spend on "8-inch skillet" or "16-inch skillet," those variants you do not carry are negative keyword candidates. The shopper's specific need does not match what you offer, so clicks from those searches are unlikely to convert.
The cadence: how often to run this
Weekly is the standard for active campaigns. Pull the 7-day search term report each Monday, apply your spend threshold, review the top candidates, and add negatives. This cadence keeps irrelevant queries from accumulating spend across multiple weeks before you catch them.
In the first 30 to 60 days of a new campaign, the search term report produces the most negative keyword candidates. This is when match types are broadest and the campaign is still discovering which searches it triggers on. Running the negative keyword process weekly during this period is particularly high-leverage. The pre-automation audit checklist covers this as one of the foundational cleanup steps before adding any additional automation layer.
Once campaigns have matured, you can extend the review cadence to bi-weekly or monthly while still pulling the report regularly for keyword harvesting. The search term report is doing double duty: surfacing new converting terms to add as positives, and surfacing non-converting terms to add as negatives. Both reviews can happen in the same weekly session.
Negative keywords and campaign structure
Negative keywords interact with campaign structure in important ways. In a discovery-harvest setup, where you run broad or auto campaigns to find new converting terms and then move high performers into exact match campaigns, negatives at the campaign level are how you prevent the same search term from triggering ads in both campaigns at once.
If a term is converting well in your exact match campaign, add it as a negative exact to your auto or broad match campaign. This keeps your spend on that term concentrated in the campaign where you have the most control over the bid. Without this cross-campaign negative structure, the same term competes against itself internally, fragmenting performance data and bidding efficiency. This principle is covered in detail in the PPC automation rules guide.
Negative keywords are maintenance work, not setup work. The first pass is the largest. Each week after that is incremental. Done consistently, it is one of the highest-ROI tasks in ongoing campaign management, because it makes every other optimization work on cleaner data.
Frequently asked questions
What are negative keywords on Amazon? Negative keywords are search terms you explicitly exclude from triggering your ads. When a shopper's search contains a negative keyword you have added, your ad will not show for that search. They prevent ad spend from going toward queries that are unlikely to convert for your product.
Where do I find negative keywords for Amazon? The search term report is the primary source. Sort by spend descending and look for search terms that spent meaningfully with zero or very few conversions. You can also add negatives proactively based on product knowledge before accumulating spend, for terms you know are irrelevant.
What is the difference between negative exact and negative phrase on Amazon? Negative exact blocks only the precise search term you enter. Negative phrase blocks any search containing your term as a phrase. Negative exact is surgical and used when a specific query is the problem. Negative phrase is broader and used when an entire topic category is irrelevant to your product.
Can negative keywords hurt my Amazon sales? Yes, if added incorrectly. A negative keyword that is too broad can block searches that were converting well. Always check conversion history before blocking a term. If a search term has converted even once, investigate before adding it as a negative.
How often should I add negative keywords on Amazon? Weekly for active campaigns, especially in the first 30 to 60 days after launch. Pull the 7-day search term report each week, sort by spend, and add negatives for terms that spent with no conversions. Cadence can slow to bi-weekly or monthly once campaigns have matured.
Negative keywords are the manual foundation. Once your account is clean, Off Hours performance rules watch for the signals that indicate efficiency is drifting, so you know when the next cleanup pass is needed. Start a free 14-day trial.