Keyword insertion is a feature in Google Ads and Microsoft Advertising that replaces a placeholder in a search ad with the keyword that caused the ad to appear. An advertiser writes a headline such as "Buy {KeyWord:Chocolate}", and the system shows "Buy Dark Chocolate" to someone whose search matched the keyword "dark chocolate". It exists to solve an old problem of scale. An ad group may hold dozens or hundreds of keywords, and writing a separate ad for each one is slow, while a single generic ad repeats nothing the searcher typed. Keyword insertion, often shortened to DKI (dynamic keyword insertion), lets one ad echo many keywords.

How the tag works

Google's syntax is a pair of braces containing the word "keyword", a colon and default text: {KeyWord:Chocolate}. When an ad serves, Google Ads tries to replace the whole tag with one of the ad group's keywords. If it cannot, it shows the default text instead.

According to Google Ads Help, the inserted text is "the keyword from your creative", not the search term, and the feature "works the same across all match types". Google's own example uses an ad group containing "dark chocolate", "sugar free chocolate" and "gourmet chocolate truffles". A search for "dark chocolate bar" produces "Buy Dark Chocolate". A search matched to "gourmet chocolate truffles" produces "Buy Chocolate", because the longer keyword would break the headline limit and the system falls back to the default.

Capitalisation is controlled by how the word "keyword" is typed inside the tag. According to Google's setup page, there are five variants:

  • keyword gives "dark chocolate", all lower case.
  • Keyword gives "Dark chocolate", sentence case.
  • KeyWord gives "Dark Chocolate", title case.
  • KEYWord capitalises the first word entirely, as in "USA Chocolate".
  • KeyWORD capitalises the last word entirely, as in "Chocolate Made In USA".

The same page lists the fields where the tag works: headlines of up to 30 characters, descriptions of up to 90 and the two display path fields of up to 15 each. Google states that "Customizers cannot be used in the Final URL field". Landing page personalisation therefore relies on separate URL parameters rather than the ad tag.

Google states that "keyword insertion can automatically correct spelling mistakes", so a keyword entered as "chocoolate" appears as "chocolate". It will not insert trademarks restricted under its trademarks policy, and it bars the feature for content promoting healthcare and sexual content. Keyword insertion is also unavailable in Dynamic Search Ads, which have no keywords to insert.

In the Google Ads API, keyword insertion is one of several built-in customizers for responsive search ads, alongside location insertion and countdowns. Google's developer documentation adds a constraint that is easy to miss: default text is used only if the default itself fits the 30 or 90 character limit.

Microsoft's version

Microsoft Advertising calls the mechanism dynamic text. Its {KeyWord:default} tag behaves much like Google's. According to Microsoft's API documentation for responsive search ads, each headline accepts up to 1,000 characters of input including dynamic text strings, but no more than 30 characters may remain after substitution, or 90 for descriptions. If the substituted text runs long, "the ad will fail to display or default text will be used".

Microsoft made the default compulsory. Its API team announced in August 2017 that from October 18 that year, new or edited ads using the keyword parameter had to include a default value. Until then, an ad whose title became too long after substitution simply did not serve.

Microsoft also supports keyword-level parameters, {Param2:default} and {Param3:default}, which pull a value stored against each keyword, such as a price, into the ad. According to Marin Software's documentation, Microsoft accepts text or numbers in these fields, whereas Google's equivalent ad parameters were numeric.

Origin and evolution

No launch announcement for keyword insertion has surfaced. By January 11, 2004, Aaron Wall of SEO Book was describing {keyword: } as an established AdWords option, noting that one of his ads had been disapproved for missing a fallback keyword. Barry Schwartz of Search Engine Roundtable wrote in August 2005 that he first learned the "trick" at the Ad Copy and Landing Page Clinic at SES New York in 2004.

In May 2006 Search Engine Roundtable reported that MSN adCenter supported keyword insertion through dynamic text, with up to three placeholders per keyword, while Yahoo did not.

For more than a decade, keyword insertion lived in short, fixed text ads, where a single headline had to carry the keyword. That changed with responsive search ads. Google introduced them in beta at Google Marketing Live 2018, and the format accepts up to 15 headlines and four descriptions that Google assembles in combinations. In July 2020 Google added location insertion and countdown customizers to responsive search ads, according to Search Engine Journal.

Expanded text ads could no longer be created or edited after June 30, 2022, leaving responsive search ads as the only new text format in Search campaigns. The older feed-based ad customizers tied to those ads stopped serving on May 31, 2024, and disappeared from Google Ads scripts on July 14, 2025. Keyword insertion survived because it lives in the ad text itself, not in a feed.

Why it matters

Keyword insertion is one of the oldest forms of automated ad text, and it shows a trade-off that still runs through search advertising: relevance at scale against control over what an ad says. For retailers with thousands of product terms, it remains a cheap way to reflect a query back to the searcher. Google's Ad Strength rating scores keyword relevance in headlines and descriptions as one of its four factors, which gives the technique a practical role in responsive search ads, although Google says the rating is not used in the auction.

Insertion also makes the advertiser responsible for words it did not explicitly type. Every keyword, including those added through Google's recommendations, becomes potential ad copy.

Limitations and disputes

The best-known criticism is that keyword insertion produces generic ads. David Szetela argued in Search Engine Watch in August 2008 that indiscriminate use leads to "diluted messages that fail to match the searcher's intent or need", and that results can be "worse than those obtainable without it". Long keywords default to bland fallback text.

The legal risks are more serious. In Australia, Employsure, a private workplace relations adviser, ran Google ads between August 2016 and August 2018 that appeared for searches such as "fair work ombudsman", a government agency. According to law firm Allens, the ads used dynamic keyword insertion "so that the language used in particular Google Ads changed in response to particular search terms". On August 13, 2021, the Full Federal Court found the ads falsely represented an affiliation with a government agency. On November 29, 2021, Justice Griffiths imposed a A$1 million penalty, well below the A$5 million the Australian Competition and Consumer Commission had sought, according to the ACCC.

Trademarks raise similar problems when an advertiser bids on a competitor's name. Courts in many jurisdictions have treated a hidden keyword differently from a trademark shown in the ad itself, and keyword insertion can turn one into the other. In Blue Bay Ventures v. John Buys Bay Homes, decided in the Northern District of California on March 13, 2026, the defendant's ads initially displayed the plaintiff's mark "apparently due to the keyword insertion feature", according to law professor Eric Goldman. The court remanded the case on standing grounds without ruling on the merits.

There is also an unresolved question about automated matching. Google's documentation describes inserting keywords from the ad group but does not state, as of October 2026, what appears when an ad is served through AI Max's search term matching rather than through a specific keyword.

Not the same as

Dynamic Search Ads. These generate headlines from a website's content and match queries without keywords. Keyword insertion depends on a keyword and does not work in them.

Text customization. Formerly called automatically created assets, this AI Max setting generates new headlines and descriptions from landing pages, existing ads and keywords. Keyword insertion fills a slot; text customization writes the text.

Dynamic headers on landing pages. A dynamic header swaps text on the destination page using URL parameters. It borrows the logic of keyword insertion but operates after the click, outside the ad.

Ad customizers. Keyword insertion is one built-in customizer. Custom attributes, location insertion and countdowns pull in other values, such as prices or dates, rather than the triggering keyword.

Recent developments

The pressure on keyword insertion now comes from generative text rather than from rival formats. Google began upgrading Search campaigns that use broad match or automatically created assets to AI Max on September 1, 2026, with text customization on by default. Generated assets refresh at least every 48 hours and are served when predicted to outperform advertiser copy, and industry executives have warned that machine-written ads converge on similar wording.

Controls over that text have arrived in stages. Text guidelines, with up to 25 term exclusions per campaign, went global on February 26, 2026. On April 30, 2026, Google added AI Brief, which lets advertisers steer AI Max in plain language. Dynamic Search Ads are scheduled to migrate to AI Max in February 2027.

As of October 2026, keyword insertion remains supported in responsive search ads on both Google and Microsoft. Its appeal has narrowed to one job: placing an advertiser-approved keyword into a known slot, with predictable fallback text. That predictability, once a limitation, is now what separates it from the generated copy around it.

Timeline

  • 2004 - Barry Schwartz learns the AdWords keyword insertion "trick" at SES New York.
  • January 11, 2004 - SEO Book describes {keyword: } as an existing AdWords option, with lower and title case variants.
  • August 30, 2005 - Search Engine Roundtable publishes keyword insertion tips, including capitalisation variants.
  • May 5, 2006 - MSN adCenter supports keyword insertion through dynamic text; Yahoo does not.
  • August 11, 2008 - David Szetela's Search Engine Watch critique of indiscriminate DKI use.
  • August 2016 to August 2018 - Employsure runs Google ads appearing for government agency searches in Australia.
  • October 18, 2017 - Microsoft makes default text mandatory for new or edited ads using the keyword parameter.
  • 2018 - Google introduces responsive search ads in beta at Google Marketing Live.
  • July 2020 - Location insertion and countdown customizers added to responsive search ads.
  • August 13, 2021 - Australia's Full Federal Court finds Employsure's ads misleading.
  • November 29, 2021 - Federal Court imposes a A$1 million penalty on Employsure.
  • June 30, 2022 - Expanded text ads and legacy ad customizers can no longer be created or edited in Google Ads.
  • February 2024 - Google completes the generative AI rollout of automatically created assets for English-language advertisers in the US and UK.
  • May 31, 2024 - Legacy feed-based ad customizers stop serving.
  • July 14, 2025 - Google Ads scripts return sunset errors for legacy ad customizer entities.
  • February 26, 2026 - Google's text guidelines become available globally.
  • March 13, 2026 - Blue Bay Ventures v. John Buys Bay Homes remanded to state court; ads had displayed the plaintiff's mark via keyword insertion.
  • April 30, 2026 - Google announces AI Brief for AI Max.
  • September 1, 2026 - Google begins upgrading broad match and automatically created asset campaigns to AI Max.
  • February 2027 - Scheduled migration of Dynamic Search Ads to AI Max.

Summary

Who: Advertisers and agencies write keyword insertion tags; Google Ads and Microsoft Advertising perform the substitution; regulators and courts, such as Australia's ACCC and Federal Court, have judged the resulting ad text.

What: A placeholder, written as {KeyWord:default text}, that replaces itself with the ad group keyword that triggered the ad, or with default text when the keyword is too long or cannot be used.

When: In use in Google AdWords by January 2004 and in MSN adCenter by 2006, carried into responsive search ads from 2018, and still supported as of October 2026.

Where: In headlines, descriptions and display paths of search text ads, but not in final URLs or Dynamic Search Ads.

Why: To make one ad reflect many keywords without writing separate copy for each, at the cost of generic phrasing and exposure to policy, consumer law and trademark risks.