Source: https://measuremy.site/blog/how-long-should-you-keep-analytics-data [measuremy.site](https://measuremy.site/) / [Blog](https://measuremy.site/blog) # How long should you keep analytics data? October 13, 2026 ยท 4 min read [Photo by Serpstat on Pexels](https://www.pexels.com/photo/silver-imac-displaying-line-graph-placed-on-desk-572056/) ## Retention is a decision, not a default Many site owners keep analytics forever because storage feels cheap. But old raw data has costs: more privacy surface, more noise, slower reporting, and more to manage if something goes wrong. The useful question is not "how long can I keep it?" but "how long does each kind of data stay useful?" A retention policy is not just a privacy checkbox. It changes how you investigate problems, how quickly dashboards load, and how much data you have to protect. ## Separate raw events from aggregates Raw events are individual pageviews, clicks, and custom events with timestamps, sources, and paths. Aggregates are counts like visits per day, signups per month, or conversion rates per landing page. Raw events are useful for debugging. Aggregates are useful for decisions. They do not need the same retention period. - Raw pageview and click events help you trace a broken funnel or a sudden [traffic spike](https://measuremy.site/guides/find-why-traffic-spiked). - Daily aggregates support dashboards and weekly reviews. - Monthly aggregates support seasonality and year-over-year comparisons. - UTM and campaign data may need different windows for attribution and signup tracking. ## Start with a short raw window For most small sites, 30 to 90 days of raw events is enough to catch problems and inspect recent campaign behavior. If a typical sales cycle is short and you review campaigns monthly, you rarely need raw detail from a year ago. If your product has a long decision cycle, you may want longer raw event history so you can trace a signup back to the first visit. But that does not mean keeping every visitor identifier forever. It means deciding what you actually need to join the dots. A better approach is to aggregate the moments that matter: - Store a daily count of visits per source. - Store a weekly count of signups per landing page. - Store a monthly count of conversions per campaign. - Keep raw event logs only for the period you are likely to debug. ## Keep aggregates longer than raw data Aggregated data is smaller, less personal, and still answers most business questions. A common pattern is to keep daily aggregates for 13 months and monthly aggregates for 25 months. That gives you the current month plus two full years of year-over-year comparison without holding a raw event log. This is not a legal requirement. It is a practical trade-off. You can choose shorter windows if you do not need seasonality. Daily data helps you see weekly patterns and recent changes. Monthly data helps you see seasons without storing every click. If you only review traffic once a quarter, you may not need daily detail for two years. ## Think about identifiers separately If your analytics uses cookies or long-lived visitor IDs, the identifier is the most sensitive part of the raw event. Long retention means you can follow someone across many visits and build a longer behavioral picture. Some cookieless tools avoid that by design. measuremy.site, for example, uses an anonymous id that changes every day, so it never follows a person across days. That changes the retention calculation because the raw identifier does not become a long-term profile. You still need a retention policy, but the identifier is less of a reason to keep raw events forever. ## Legal and privacy obligations Privacy rules differ by region and by the type of site. Some frameworks encourage data minimization and purpose limitation. Others set specific rules for certain sectors or certain types of data. Do not assume a single number is safe everywhere. If you collect data from visitors in multiple jurisdictions, or if you handle account data alongside analytics, check your own legal position. A sensible retention policy is useful evidence of data minimization, but it does not replace specific advice. ## Watch out for data that grows stale Traffic sources change. Browsers, devices, and campaign URLs change. A pageview from three years ago tells you little about today's visitors. Keeping it may not improve decisions; it just adds volume. Old data can also mislead if you compare different tracking setups or site structures. A page that was popular before a redesign may not be the same page now. A campaign tagged with a broken UTM parameter may look like a source that never existed. Deleting old raw data can force you to rely on the aggregates that actually matter. ## A simple example policy Use this as a starting point, not as legal advice: - Keep raw pageview and click events for 60 days. - Build daily aggregates for 13 months. - Build monthly aggregates for 25 months. - Keep campaign click detail until 30 days after the campaign ends. - Keep signup attribution as aggregate counts, not raw visitor histories. - Delete raw logs automatically after the retention window. ## Put the policy into practice A retention policy only helps if it runs without you remembering to do it. - Build aggregate tables before raw data is deleted. - Automate deletion or aggregation on a schedule. - Document what each metric means so future you can rebuild it. - Test dashboards after old data is removed. - Review the windows once a year or when your product changes. If your analytics tool does not export aggregates easily, you can export raw data to a spreadsheet and aggregate there before deleting. The goal is not perfection. It is having a repeatable process. Retention is not about keeping everything or deleting everything. It is about matching the detail you keep to the questions you actually ask. For most small sites, a short raw window and longer aggregates gives you enough history to plan while reducing the amount of data you have to protect. ### See it on your own site measuremy.site is cookieless analytics your coding agent can read. 30-day free trial, no card. Plans from $9/month. [Start free trial](https://measuremy.site/login) [See the live demo](https://measuremy.site/share/measuremy.site) Add measuremy.site analytics to this project: connect the measuremy.site MCP server at https://a.measuremy.site/mcp for all my projects (claude mcp add --scope user; it signs in with OAuth, no key, and one sign-in covers every site), then tell me how to sign in. Details: measuremy.site/llms.txt ## Free tools - [Analytics tag checker](https://measuremy.site/tools/analytics-tag-checker): Which analytics and pixels a site runs, plus duplicate and broken tags. - [Free UTM link builder](https://measuremy.site/tools/utm-link-builder): Add utm_source, medium and campaign to any link. - [Website traffic checker](https://measuremy.site/tools/website-traffic-checker): A site's popularity rank and estimated monthly visits. [All free tools](https://measuremy.site/tools) ## More from the blog - [How to calculate your website conversion rate, and what to compare it to](https://measuremy.site/blog/calculate-website-conversion-rate) - [Is my A/B test result significant? A plain-English guide with a worked example](https://measuremy.site/blog/is-my-ab-test-significant) - [What is bounce rate, how is it calculated, and is yours a problem?](https://measuremy.site/blog/what-is-bounce-rate) - [How to add a visitor counter to your website or GitHub README](https://measuremy.site/blog/add-visitor-counter-to-website) - [How much traffic does a website get? How to estimate any site's visits](https://measuremy.site/blog/how-much-traffic-does-a-website-get) - [How to track QR code scans: count them, and see which poster worked](https://measuremy.site/blog/track-qr-code-scans) - [How to see how many people clicked your link (without a paid shortener)](https://measuremy.site/blog/how-many-people-clicked-my-link) - [How to check if your Google Analytics 4 tag is installed (and only counting once)](https://measuremy.site/blog/check-if-ga4-is-installed) - [Why GA4 shows your campaign traffic as Unassigned (and how to fix the links)](https://measuremy.site/blog/ga4-unassigned-traffic) - [Does your redirect keep your UTM tags? How to check before a campaign goes out](https://measuremy.site/blog/redirect-drops-utm-tags) - [How I built a self-hosted analytics MCP server on Cloudflare Workers and D1](https://measuremy.site/blog/analytics-mcp-server-cloudflare-workers) - [UTM tracking explained: what the parameters mean and how to use them](https://measuremy.site/blog/utm-tracking-explained) - [Conversion funnel analysis for small sites: a practical guide](https://measuremy.site/blog/conversion-funnel-analysis) - [Sudden drop in website traffic? A checklist for finding the cause](https://measuremy.site/blog/sudden-drop-in-website-traffic) - [What is an MCP server? A plain-English guide for people who run websites](https://measuremy.site/blog/what-is-an-mcp-server) - [Adding an MCP server to Claude Code](https://measuremy.site/blog/how-to-add-an-mcp-server-to-claude-code) - [How to Build a Small MCP Server That Actually Helps](https://measuremy.site/blog/how-to-build-your-own-mcp-server) - [How to Find the Biggest Drop Off in a Funnel](https://measuremy.site/blog/how-to-find-the-biggest-drop-off-in-a-funnel) - [What Is the Urchin Tracking Module?](https://measuremy.site/blog/what-is-the-urchin-tracking-module-and-why-utm-stuck-around) - [What Microsoft MCP servers actually do](https://measuremy.site/blog/microsoft-mcp-servers-explained) - [UTM parameters for email newsletters](https://measuremy.site/blog/utm-parameters-for-email-newsletters) - [Track Button Clicks Without Google Tag Manager](https://measuremy.site/blog/how-to-track-clicks-on-a-button-without-google-tag-manager) - [How to track the results of a social media post without cookies](https://measuremy.site/blog/how-to-measure-the-results-of-a-social-media-post) - [How to track traffic from a GitHub README](https://measuremy.site/blog/how-to-track-traffic-from-a-github-readme) - [How to measure a product launch without guessing](https://measuremy.site/blog/how-to-measure-a-product-launch)