Small things that do one job. They run in your browser, so nothing you paste is uploaded or stored, and none of them ask for an account.
Paste show lldp neighbors or show cdp neighbors output and get a Mermaid topology diagram you can commit next to your configs.
It reads LLDP and CDP from several devices at once and merges links seen from both ends.
flowchart TD
acc_sw01["acc-sw01"]
core_sw01["core-sw01"]
core_sw02["core-sw02"]
ap_2f_01["ap-2f-01"]
edge_rtr01["edge-rtr01"]
wlc_01["wlc-01"]
acc_sw01 ---|"Gi1/0/48 to Gi1/0/1"| core_sw01
acc_sw01 ---|"Gi1/0/47 to Gi1/0/1"| core_sw02
acc_sw01 ---|"Gi1/0/12 to GigabitEthernet0"| ap_2f_01
core_sw01 ---|"Ten1/1/1 to Gig0/0/0"| edge_rtr01
core_sw01 ---|"Po1 to Po1"| core_sw02
core_sw02 ---|"Gi1/0/10 to Gi0/0/1"| wlc_01The sample paste on the tool page generates this diagram and its Mermaid source.
Paste a Cisco IOS running-config and get a structured record: interfaces, addressing, VLANs, trunks, static routes, OSPF, BGP, and services.
Masks come with prefix lengths. Sections the model does not carry are listed rather than dropped without a word.
Paste a running-config or show output and get it back with the passwords, keys, communities, certificates, serial numbers, and public addresses replaced by placeholders.
Repeated values keep the same placeholder, so the config still reads the way it did. Private addressing is left alone.