The App Store keyword field: how to use all 100 characters

The keyword field is 100 characters of text that nobody sees but Apple's search does. Use it for search terms that do not already appear in your app name or subtitle, separate them with commas and no spaces, and leave out other apps' names. Done well, those 100 characters can add dozens of searches you show up for.

What the keyword field is

In App Store Connect, every version of your app has a Keywords field next to the name, subtitle and description. Apple's limit is 100 characters, with terms separated by commas. The field is not shown on your product page; it only feeds search.

Apple counts three pieces of your listing as the main text for search: the app name (30 characters), the subtitle (30 characters) and the keyword field (100 characters). That is 160 characters in total, and the keyword field is more than 60% of it.

Promotional text, the 170 character line above your description, does not affect search. Apple says so directly, so do not spend effort putting keywords there.

The four rules that save the most space

1. Commas, no spaces. surf,tide,wave fits in 14 characters. surf, tide, wave takes 16. Across a full field, spaces after commas can waste 10 to 15 characters.

2. Do not repeat your name or subtitle. Words in your app name and subtitle already count for search. Repeating them in the keyword field spends characters on words Apple already has. If your name is "Driftwood: Surf Forecast", the words surf and forecast are already covered.

3. Single words beat phrases. In practice, Apple matches searches against the words across your name, subtitle and keyword field together. If you have surf in your name and report in the keyword field, you can show up for "surf report" without spending 11 characters on the full phrase.

4. No competitor or trademark names. App Review Guideline 2.3.7 asks you not to pack metadata with trademarked terms or other apps' names. Listings get rejected for it, and it rarely works anyway.

How to fill the field, step by step

1. List what people search. Write down every phrase someone might type to find an app like yours. Aim for 30 to 50 phrases.
2. Break phrases into words. "Tide times app" becomes tide, times, app.
3. Cross out words already in your name or subtitle.
4. Order by value. Put the words most tied to what your app does first. If you run out of room, the words you drop should be the weakest.
5. Join with commas and count. You want 95 to 100 characters. An unused 20 characters is 20% of your hidden search space left empty.
6. Check it. Before you submit, run it past a checker that flags repeats, spaces and length. Altitude's listing check does this for your title, subtitle and keyword field together.

A worked example

Here is a fictional surf app, "Driftwood: Surf Forecast", with the subtitle "Swell report, wind and tides".

A first draft keyword field might look like this. It uses all 100 characters:

surf, surf report, swell, tide times, wave height, beach weather, wind, surf cam, spots, buoy, ocean

After the four rules:

• surf, swell, wind and report are already in the name or subtitle, so they go.
• Phrases become single words, and repeated words appear once.
• Spaces after commas go.

The result, at 84 characters:

tide,times,wave,height,beach,weather,cam,spots,buoy,ocean,bodyboard,kite,break,chart

It covers every search the first draft did, adds 4 new words, and still leaves 16 characters for more.

How to tell if it worked

Change the field, ship the version, then watch ranks for the words you added over the next 7 to 14 days. Ranks move a little every day for reasons that have nothing to do with you, so a single day tells you very little. Why your App Store rank moves every day covers how to read those moves.

Altitude tracks every keyword your listing could rank for, checks the top 200 results each day, and shows which words moved after a release. You can add your app and see your current ranks in about a minute.

Questions

Does the keyword field use characters or bytes?

Apple's product page guide describes 100 characters. Some App Store Connect reference pages describe 100 bytes, which matters for languages that use more than one byte per character. Trust the counter in App Store Connect.

Do I need both singular and plural forms?

Many developers find that one form is enough for most words, and space is tight. If a plural is how people really search, test it and watch the rank.

Can I change keywords without a new version?

No. The keyword field is tied to an app version, so changes go live with your next approved version. Promotional text is the field you can change at any time, and it does not affect search.