Overlap merge
- 10.0.0.0/24 + 10.0.0.128/25 -> merged to 10.0.0.0 - 10.0.0.255
developer validator
CIDR Merge & Dedup
Merge overlapping/adjacent IPv4/IPv6 CIDRs into clean ranges—client-side only.
Results
Paste input and validate locally.- Status
- Ready when you validate.
- Details
- Ready when you validate.
- Merged ranges
- Ready when you validate.
- Ranges count
- Ready when you validate.
- Families
- Ready when you validate.
Rules & checks
Parses IPv4 and IPv6 CIDRs; processes each family separately.
Merges overlapping or directly adjacent ranges into a single range.
Outputs merged start/end ranges; no data leaves your browser.
When to use it
- Normalize firewall or security group inputs
- Sanity-check user-entered CIDR lists in dashboards
- Prep allowlists/denylists to reduce duplicate entries
Tips
- Keep IPv4 and IPv6 blocks separate in your documentation
- Use the CIDR to Range converter if you need explicit endpoints
Examples
Separate ranges
- 10.0.0.0/24 + 10.0.2.0/24 -> two ranges
IPv6 merge
- 2001:db8::/64 + 2001:db8::/65 -> one merged range
FAQs
- Is anything uploaded?
- No. Merging happens entirely in-browser/offline.
- Do you return minimal CIDR summary?
- We return merged ranges (start–end). Use a summarizer if you need minimal CIDR sets.
Related validators
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CIDR Validator
Validate IPv4/IPv6 CIDR blocks and view the normalized network address.
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CIDR to Range Converter
Convert IPv4/IPv6 CIDR blocks to explicit start/end ranges client-side.
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CIDR Overlap Checker
Check whether two IPv4/IPv6 CIDR blocks overlap—runs entirely client-side.
Range-level merge/dedup only; does not test reachability or routing.