How to Select and Optimize Amazon Backend Keywords

TL;DR

What are Amazon backend keywords?

Backend keywords (or “Search Terms”) are hidden text fields in Amazon Seller Central that allow sellers to index their products for relevant search queries—such as synonyms, abbreviations, or hyper-specific use cases—that do not appear in the visible product title or bullet points.

What is the specific limit for backend search terms?

The limit is strictly 500 bytes, not characters. While standard English letters count as 1 byte, special characters or symbols can count as 2-4 bytes. If a seller exceeds this limit by even a single byte, Amazon’s algorithm may de-index the entire field, resulting in zero SEO benefit.

What words must be excluded to avoid penalties?

Sellers must strictly avoid competitor brand names (which violate IP policies), repeated words already present in the listing’s frontend (redundant), subjective claims like “best” or “cheapest,” and unnecessary punctuation (commas) or filler words (like “a,” “and,” “the”).

How do backend keywords impact ranking in 2026?

Backend keywords expand a product’s “searchability” by helping Amazon’s A9 algorithm and Rufus AI understand context. They allow products to rank for intent-based voice searches and loose-match queries that would otherwise be missed, directly increasing traffic and organic visibility.

In the highly competitive world of Amazon selling, standing out in search results is crucial. While many sellers focus on visible keywords in product titles and descriptions, Amazon backend keywords are an equally important, yet often overlooked part of your Amazon SEO strategy. These hidden search terms play a pivotal role in ensuring your product reaches the right audience.
This guide will help Amazon sellers understand what backend keywords are, why they matter, and how to optimize them to improve product visibility and boost sales. Let’s dive into the details and discover how to master Amazon Backend Search Terms.

Amazon backend keywords are hidden search terms that sellers input into their product listing’s backend. Unlike visible keywords in titles or bullet points, backend keywords are not displayed to customers, but are indexed by the Amazon A9 algorithm to determine product relevance.

Backend vs. Front-Facing Keywords

Front-facing keywords: Appear directly on your product page and contribute to readability.
Backend keywords: Hidden and work behind the scenes to enhance search coverage by targeting additional search terms, synonyms, and variations without cluttering your listing with repetitive or unnecessary words.

Examples of Backend Keywords

Backend keywords can include a list of relevant terms that are likely used by shoppers by products similar to yours. Do not forget these type of keywords:

• Synonyms (e.g., “running shoes” for “sneakers”)
• Misspellings (e.g., “backpak” for “backpack”)
• Foreign language terms (e.g., “zapatos” for a product targeting Spanish-speaking customers)

These keywords expand your product’s discoverability by capturing diverse search queries.

Why Are Amazon Backend Search Terms so Important?

Boost Product Visibility

Backend keywords help your product appear in search results for terms that may not fit naturally into your visible content. By strategically including alternative keywords, you can reach a broader audience.

Avoid Keyword Clutter

Using backend keywords prevents keyword stuffing in your product titles and descriptions, maintaining a clean and professional appearance for your listing.

Target Alternative Search Terms

Backend keywords let you include variations, misspellings, and secondary languages, to ensure your product is discoverable by different segments of your target audience. For example, a single product can rank for both “diaper bag” and “nappy bag” using backend keywords.
For sellers looking to fine-tune this process, Amazon Search Term Optimization can help identify untapped opportunities to boost discoverability.

How to Find the Right Amazon Backend Keywords

Popular Backend Keyword Research Tools

Use Amazon SEO Tools like Helium 10, Jungle Scout, or MerchantWords to generate keyword ideas. These tools provide data on search volume, competition, and relevance.

Competitor Analysis: Amazon Sellers that Compete in the same Space

Study your competitors’ listings to identify high-performing keywords they are using. Pay attention to their descriptions, bullet points, and customer reviews.

Gain Insights from Amazon Customer Reviews and Q&A Sections

Analyze reviews and Q&A sections to discover terms that customers frequently use to describe your product. These can offer valuable insights into user intent.
You can also use Reverse ASIN Lookup Tools like Helium10’s Cerebro to reverse keyword search Amazon to find out what keywords your potential competitors in your category are ranking for.
Follow these simple steps to narrow down your search term volume:

Focus on Top Results: Look at the first 3 organic searches, and sort results by high search volume and high relevancy, such as the Cerebro IQ score from Helium 10.

Apply Basic Filters: Set filters like a minimum search volume of 1000, a maximum rank of 20, and word count of 2

Export and Organize: Export the data as an excel sheet. Filter by search volume in descending order, then filter by ranks, and exclude any ‘null’ values, and sort it in ascending orders

Refine Keywords: Keep the first 100 keywords, remove duplicates, common words or phrases you want to remove, and convert them to lowercase. Amazon Keywords Processor tools like Helium 10’s Frankenstein will be handy here when combining and cleaning up backend keywords.

Final Selection: Remove any brand names and/or repetitive words and reduce the search terms to 505 characters max before inputting them into your backend search term box. Please note: the maximum limit for adding backend keywords used to be 250 bytes or around 250 characters, but in early 2024 Amazon extended this limit to 500 characters!

Types of Keywords to Include

• Synonyms: Capture alternative ways customers might search for your product.
• Misspellings: Include common typos that customers might enter.
• Long-Tail Keywords: Use specific, multi-word phrases to target niche search intents (e.g., “waterproof hiking backpack for women”).
• Foreign Language Terms: Incorporate keywords in other languages, particularly for products sold in multilingual markets.

Amazon’s Guidelines for Backend Keywords

Amazon sets specific rules for backend keywords to ensure they enhance search performance without misuse:

• Limit backend keywords to 500 characters maximum per listing
• Avoid prohibited terms like offensive words, competitor names, or trademarks
• Do not repeat words already present in visible content

Best Practices for Backend Keywords

• Exclude Product Identifiers: Avoid brand names, product names, ASINs or UPC codes.
• Stay Relevant: Focus on terms directly related to your product. Irrelevant keywords can hurt your indexing and credibility.
• Avoid Duplication: Exclude terms already used in titles, bullet points, or descriptions.
• Logical Combinations: Group related keywords logically to maximize search coverage without exceeding character limits. Customers are more likely to search for “big stuffed teddy bears” than for “teddy stuffed bears.”
• Use Spaces Only: Separate keywords with single space, avoiding commas or other punctuation.
• Exclude Temporarily True Statements: Avoid terms like “new”, “on sale” or “available now”.
• Avoid Subjective Claims: Skip words like “amazing” or “good quality”.
• No Common Misspellings: Amazon’s algorithm accounts for common misspellings, capitalization and pluralization automatically.
• Include Alternate Names: Include abbreviations or alternate product names, tops and key characters (for books and movies) to capture different search queries.

Quick Guide: How to Add Backend Keywords on Amazon Seller Central

Log into Seller Central: Access your account and navigate to the product listing you want to optimize.

• Edit Product Listing: Click “Edit” next to the product and go to the “Keywords” tab in the backend.
• Enter Backend Keywords: Add search terms in the “Search Terms” field, separated by spaces.
• Save Changes: Click “Save and Finish” to update your listing.

Tips for Organizing and Prioritizing Backend Keywords

Prioritize high-impact keywords first and group keywords by themes or categories to cover various search intents. Bonus Tip: Input additional search terms in “Subject Matter” and “Other Attributes” for better results. As for the “Intended Use” and “Target Audience” fields, we recommend leaving it blank so it doesn’t limit the search exposure of your product listing.

Keyword Indexing: The Basics

Examples of Backend Keywords

Keyword indexing refers to the process by which Amazon’s algorithm recognizes the relevance of your keywords and includes them in its search results. If a keyword is not indexed, your product will not appear in search results for that term.

Factors Impacting Keyword Indexing

• Relevance: Keywords must align with your product’s category and attributes.
• Avoid Duplication: Repeating keywords in both backend and visible content can waste space without improving indexing.
• Prohibited Terms: Using banned keywords can result in non-indexing or listing penalties.

How to Check Whether Keywords Are Indexed

Search terms deemed relevant may change over time as Amazon gathers data. Regular Amazon listing audit help identify areas for improvement to maximize the potentials of your backend keywords.

Manual Method

Search for your product using its ASIN and a specific keyword in Amazon’s search bar (e.g., “ASIN + keyword”). If your product appears in the results, the keyword is indexed.

Checking via 3rd Party Tools

Use tools like Helium 10’s Index Checker or AMZ One Step provide automated ways to verify whether your backend keywords are indexed.

Troubleshooting Non-Indexed Keywords

There are a few things you can do to try and resolve backend keyword indexing issues. We suggest starting with:

• Replace non-indexed keywords with more relevant alternatives
• Ensure your backend keywords follow Amazon’s guidelines

Optimizing Backend Keywords for Amazon’s AI (Rufus) and Voice Search

Amazon is speeding up the integration of Generative AI. Specifically via its shopping assistant Rufus and also Alexa driven voice search. As a results, the way customers discover products on the e-commerce platform is changing. Rather than mapping static keywords to your products, your targeting strategy needs to evolve to also cover conversational product discovery. While traditional keywords remain vital, your backend strategy must now account for natural language queries and voice-activated searches via Alexa.

To capture this traffic, you need to think less like a database and more like a human assistant.

• Target Question-Based Queries: Voice searches are often phrased as questions. Instead of just “waterproof boots,” consider including backend terms that answer specific needs, such as “boots for hiking in rain” or “shoes that keep feet dry.”
• Focus on Context and Intent: Amazon’s Large Language Models (LLMs) analyze the relationship between words. Use your backend fields to connect your product to specific use cases that might not fit in your bullet points. If you sell a kitchen knife, add terms related to specific tasks like “carving thanksgiving turkey” or “slicing hard vegetables” to align with intent-driven searches.
• Conversational Phrasing: While you should not use filler words (like “a,” “an,” “the”) to save space, grouping keywords that form natural associations helps AI algorithms understand context. For example, “running jogging marathon training” signals a cluster of related activities better than scattered, unrelated terms.

Expand your Keyword Coverage & Master Ancillary Keyword Fields

Many sellers falsely assume that they are done once they have completed the generic “Search Terms” field in the Amazon backend. This can be a huge mistake and you may be leaving valuable indexing real estate on the table! Depending on your category, Amazon provides additional fields such as “Target Audience,” “Subject Matter,” and “Other Attributes.” These fields are often given higher relevance weight by the A9 algorithm for specific filters.

• Subject Matter: This field is powerful for describing what your product is visually or conceptually, rather than just what it does. For a leather journal, “Subject Matter” could include “vintage diary,” “travel log,” or “daily planner.” Unlike the general search terms box, this field helps populate the specific attribute filters customers use in the sidebar navigation.
• Target Audience: Use this to define who the product is for. Avoid generic terms like “everyone.” Be specific: “college students,” “left handed chefs,” “expecting mothers,” or “corporate gift givers.” This helps Amazon show your product to shoppers who have personalized their browsing preferences.
• Intended Use: This field connects your product to an activity. A yoga mat isn’t just a mat; its intended use includes “pilates,” “meditation,” “home gym flooring,” or “outdoor camping padding.” Filling this out improves your visibility when customers filter by usage scenarios.

Don’t Confuse Backend Keyword Character Limit with Keyword Byte Limit

Many US sellers are confused as to how many backend keywords they can actually add. The confuse character count with byte count. While character count is a good approximations, it is just an approximation! Amazon actually limits the backend keywords to exactly 500 bytes, not necessarily 500 characters. In standard English (ASCII), one character equals one byte. However, special characters and symbols can “weigh” more, potentially truncating your keywords unexpectedly.

• The “Weight” of Characters: Standard letters (A-Z) and numbers (0-9) are 1 byte. However, accented characters (like é, ü, ñ) or symbols (™, ©) typically take up 2 to 3 bytes each. A backend string containing “jalapeño” uses 9 bytes, not 8.
• The Truncation Risk: If your backend search terms string exceeds 500 bytes even by a single byte, Amazon may ignore the entire field, not just the excess words. This results in zero indexing for that field.
• Best Practice: Always check the byte count of your final string using a byte-counter tool rather than a simple word count. Avoid using unnecessary punctuation (commas, dashes) as they consume bytes without adding SEO value; single spaces are sufficient separators.

Rotate Backend Keywords Based on Seasonal Factors

Many sellers “set and forget” their backend keywords. There may be certain product categories where this is fine, but in most cases backend keywords should not be static! By ignoring seasonal search trends you are at risk of missing opportunities during peak shopping events. Implementing a seasonal rotation strategy allows you to capture high-volume, temporary traffic without cluttering your frontend listing.

Depending on your category, these trends may be driven by weather and/or temperature changes (think of blenders that may be used to prepare juices during the summer, but soup related products during the winter months), gifting occasions or national holidays. Here some general recommendations:

• The Q4 Swap: In October, review your backend keywords. Remove low-performing, generic terms to make room for “stocking stuffers,” “christmas gifts for dad,” “hanukkah presents,” or “white elephant gift ideas.”
• Event-Specific Terms: For Prime Day or Back-to-School season, rotate in terms like “dorm room essentials,” “teacher appreciation,” or “summer vacation gear.”
• Post-Season Cleanup: It is critical to remove these terms immediately after the event passes. “Christmas gift” is a wasted keyword in February and can hurt your relevance score (and conversion rate) if your product shows up for Valentine’s shoppers looking for something else. Create a calendar reminder to revert or update your backend terms on January 2nd.

Prioritize Mobile Searches when Picking Backend Keywords

Over 70% of Amazon shoppers visit the site via mobile devices. On mobile devices, user behavior is quite different as compared to desktop. Search queries tend to be shorter and more prone to typos. Also decision making is often more impulsive as it is more difficult to open multiple tabs and to start a more comprehensive brand or products comparison. Also, shoppers may be commuting, or “killing time” when using their smartphones while hoping to complete their purchase by the time they need to shift attention away from their mobile devices.

• Prioritize “Thumb-Friendly” Keywords: Mobile users often type fewer characters. Ensure you are indexed for shorter abbreviations and colloquialisms (e.g., “bday gift” vs “birthday present,” “specs” vs “spectacles”).
• Typo-Tolerance: While Amazon automatically corrects many common misspellings, mobile typing errors are rampant. Including severe but common distinct misspellings in your backend (that Amazon doesn’t auto-correct) can be a defensive strategy to capture traffic from hasty typists.
• Local Intent: Mobile users frequently use location-based intent even on Amazon. While you can’t target “near me,” you can add descriptors that imply portability or immediate need, such as “travel size,” “portable,” “compact,” or “car accessory,” which align with on-the-go mobile mindsets.

Common Mistakes to Avoid When Optimizing Backend Keywords

Overloading the Backend with Irrelevant or hard-to-rank for Keywords

Adding unrelated terms can confuse Amazon’s algorithm and hurt your ranking. Focus on relevance and avoid repeating keywords already present in titles or bullet points to maximize the use of your character limit.

Ignoring Amazon’s Restrictions

Using prohibited terms or exceeding character limits can result in penalties or non-indexing.

Recap: Level Up Your Amazon Backend Keywords Strategy

Amazon backend keywords are a powerful tool for enhancing product visibility and driving sales, and is as important as Amazon SEO and PPC. By understanding their importance, researching effectively, and following best practices, you can ensure your products reach the right audience.

For busy sellers looking to maximize their results effectively, check out our professional Amazon SEO Services and Amazon Listing Optimization Services.

Start optimizing your backend keywords today for maximum discoverability and success on Amazon!

FAQ: Amazon Backend Keywords