Prepare a focused shortlist
Open the Bulk Domain Age Checker and check the batch limit shown on the page. Paste names or HTTP(S) URLs separated by line breaks, spaces, or commas. Work in small batches so that each result remains easy to review.
The tool normalizes inputs to registered domains and removes duplicates after normalization. For example, example.com, www.example.com, and https://blog.example.com/post/ all refer to the same registered domain for this lookup. They do not produce three independent ages.
Before checking, keep your original list somewhere if paths, subdomains, or the reason for including each entry matter to your research. Those details are not separate domain registrations.
Run the comparison
- Paste the shortlist into Domains to compare.
- Select Check domains and watch the progress indicator.
- Review each row, including validation failures or unavailable records.
- Sort using the relevant column, such as age or registration date.
- Export completed results when your batch finishes.
Each lookup stands on its own. One unsupported extension or temporary registry failure does not establish anything about the remaining entries. A failed row should be investigated or labeled unresolved rather than silently removed from your working dataset.
Choose the right comparison
Sort by age when you want to compare the creation dates that were returned. Use expiration dates to identify records needing account-level review, not as a guaranteed release calendar. A missing age is not zero days old, and an unavailable expiration date is not evidence of an indefinite registration.
For a competitor review, pair registration data with a separate description of each site’s current purpose. For a portfolio review, compare public expiry information against the accounts you manage. For an acquisition shortlist, use the aged-domain checklist.
Keep a useful CSV
The export includes the domain, age, total days, registration and expiration dates, updated date, registrar, statuses, nameservers, DNSSEC reporting, retrieval time, source, and errors. Preserve the original file before editing it in a spreadsheet.
Add your own research columns separately: why the domain is included, which evidence remains missing, and what you plan to check next. Keep dates in a consistent format when importing so that spreadsheet software does not silently reinterpret them using a different locale.
Account for time and missing data
Registries can limit requests, and results may be served from a short-lived cache. The retrieval timestamp describes when the record was obtained. If you need a fresh comparison later, run a new batch and keep it as a separate dated export.
The checker does not continuously monitor a portfolio, send alerts, or provide traffic and backlink measurements. Treat the export as a registration-data snapshot. See lookup troubleshooting for retry guidance and ICANN’s RDAP overview for background on the underlying data protocol.