In this guide
- Browsers cap cookies. Chrome limits any cookie to 400 days. Safari cuts script-set cookies to about 7 days.
- A cookie set by your server in an HTTP response lasts longer than a script cookie, but Safari can still cap it in some cases.
- Open Tracked's Cookie Keeper (every plan) keeps cookies on your server and gives them back, up to 400 days for the platforms you choose.
Cookies are how analytics and ad tools recognise a visitor who returns. If the cookie disappears early, the visitor looks new and the sale is attributed to nothing. Extending cookie life is one of the clearest benefits of server-side tracking, but it has limits and traps. This page explains which cookies matter, what the server can do, and how to restore what the browser deletes. For the Safari details read Safari ITP.
The cookies that matter
| Cookie | Set by | Used for | Typical default life |
|---|---|---|---|
_ga and _ga_* | Google tag in the browser (JavaScript) | GA4 client and session | 2 years, but capped at 7 days in Safari |
FPID | Your server (GA4 client in the server container) | First-party GA4 client ID | Up to 2 years, set in an HTTP response |
_fbp | Meta pixel (JavaScript) | Meta browser ID | 90 days, capped in Safari |
_fbc | Meta pixel, from fbclid | Meta click ID | 90 days |
_gcl_au, _gcl_aw | Google Ads tags | Ads conversion linking | 90 days |
_ttp | TikTok pixel | TikTok browser ID | 13 months |
Lifetimes are from the vendors' documentation at the time of writing and can change.
Check your tracking in one pass
This is an example. Run the check on your own site to see where yours stands.
What your server can do
- Set cookies in an HTTP response. The GA4 client of a server container sets
FPIDthis way, and tags can set others. - Refresh cookies on every visit. Each response can extend the expiry, so active visitors stay recognised.
- Use a first-party subdomain. The cookie belongs to your own domain.
Where the limits bite
3 things to remember
Scroll and the points stack up.
Browsers cap cookies. Chrome limits any cookie to 400 days. Safari cuts script-set cookies to about 7 days.
A cookie set by your server in an HTTP response lasts longer than a script cookie, but Safari can still cap it in some cases.
Open Tracked's Cookie Keeper (every plan) keeps cookies on your server and gives them back, up to 400 days for the platforms you c
Restore cookies with Cookie Keeper
Cookie Keeper keeps the platform cookies on your tagging server under a hash of an identifier, and sets them again when the same visitor returns without them. In Open Tracked:
- Turn on the Data Store first. Cookie Keeper keeps the cookies there.
- Choose for each platform whether its cookie is Extended (kept up to 400 days) or not.
- Choose how the visitor is recognised: a customer ID, a cookie, local storage, a JavaScript variable or a page element, and give its name.
- On the Business plan and up, add custom cookies (a name and the days to keep).
- Save, press Generate and use the new head code on your site.
- Download the GTM files from the Setup Wizard and import them into your web and server containers.
- Press Test this power-up.
Verify in GTM Preview: delete the _fbp cookie, reload the page, and the server container sets it again from the Data Store. Cookie Keeper is available on all plans, including Free, with custom cookies from Business.
What to watch
- Consent. Restoring a cookie is still storing information on the device. Make it conditional on consent.
- Privacy notice. Say how long you keep identifiers.
- Data Store size. The store holds 1,000 keys on Free, 50,000 on Pro, 500,000 on Business and 5 million on Enterprise.
Terms you will see
- HTTP response cookie
- A cookie sent by the server with
Set-Cookie, as opposed to one written by a script. - First-party cookie
- A cookie that belongs to the site you are visiting.
- FPID
- The first-party client ID cookie set by a server container.
- Cookie expiry
- The date after which the browser deletes the cookie.
- Restore
- Setting a deleted cookie again from a copy kept on your server.
A quick test of your own cookies
Open your site in Chrome and Safari
Use a normal window.
Open the cookie list
In Chrome developer tools, Application, Cookies. In Safari, Develop, Show Web Inspector, Storage.
Read the expiry date
Note it for _ga, _fbp and FPID.
Come back after eight days
Check which cookies are still there on an iPhone.
Orders from your store, back to the ad that earned them
Your store sends the order once. Open Tracked passes it on to each ad platform, cleaned and deduplicated.
Frequently asked questions
How long can a cookie last?
Chrome limits any cookie to 400 days. Safari caps script-set cookies at about 7 days.
Does a server-set cookie last longer?
Usually yes, but Safari can still cap it at 7 days if the server's IP does not match your site's.
What is FPID?
A first-party ID cookie set by the GA4 client in a server container, used instead of the script-set client ID.
What does Cookie Keeper do?
It keeps your platform cookies on your server and restores them for returning visitors, for up to 400 days.
Is it on the free plan?
Yes. Cookie Keeper is on every Open Tracked plan, with custom cookies from the Business plan.
Do I need spreadsheets to read my results?
No. Once tracking is live, the Open Tracked analytics shows spend, revenue, ROAS and profit, and you can ask Ari, the built-in AI assistant, questions about your own numbers in plain words. Ari's allowance depends on your analytics plan.
Is Open Tracked different from Open Track or Open Space Track?
No. Open Tracked is the official name of our server-side tracking platform, and the website is opentracked.io. Many people search for it as Open Track, OpenTrack or Open Space Track. All of them lead to the same product: server-side Google Tag Manager hosting, first-party analytics and a CRM pipeline.
Fix your tracking at the source
Open Tracked hosts your server-side Tag Manager, keeps first-party cookies alive and shows what each ad is really worth.
The Open Tracked team
We build Open Tracked: server-side tracking hosting, analytics and the tools around them, for stores that spend on ads. Questions about this guide, or an idea for the next one?
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