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Updated Jul 15, 2026

Utilities

Shape URL lists into level-scoped host sets

Filter or extract domains from URLs by subdomain level.

Agent
Reduce a URL list to root domainsExtract one subdomain levelFocus on the busiest parent domains

overview

What dsieve does

Place dsieve between enumeration and probing when a URL or domain list must be normalized by subdomain level before httpx or similar.

Select depths with -f using Python slice notation, or collapse noise with -top so only the busiest parents and their children remain.

Trickest runs dsieve as a managed Utilities node: -i or -if in, folder and file out. Use duplicut for unordered wordlist dedupe and anew for append-only merges; neither replaces level-aware shaping.

source github.com/popovicn/dsieve

use cases

Where dsieve fits

Reduce a URL list to root domains

Filter a messy list of URLs to their level-2 apex domains with -f 2, giving the next stage a clean, deduplicated set of targets to work from.

Extract one subdomain level

Use -f with Python slice notation to pull out exactly the level you need, scoping a probe to second-level, third-level, or a whole range of names.

Focus on the busiest parent domains

Keep only the top X parents at a level with -top and return their children, cutting a sprawling enumeration output down to the hosts that matter most.

Normalize hosts between recon stages

Slot dsieve between discovery and probing so httpx and downstream scanners run against a scoped, level-consistent host set instead of raw URLs.

reference

dsieve inputs and flags

4 inputs
NameTypeFlagDescription
inputSTRING-iInput URL or domain.
input-fileFILE-ifInput file path, one URL or domain per line.
filter-levelSTRING-fFilter domain level. Use Python slice notation to select a range.
topSTRING-topOnly consider the top X subdomains of a certain level and return all their subdomains.

Showing key inputs. dsieve exposes 4 inputs in total.

example

Run dsieve

dsieve · command
# extract level-3 subdomains from a URL listdsieve -if urls.txt -f 3
sample output
api.example.comapp.example.comblog.example.comcdn.example.comdev.example.commail.example.comshop.example.comvpn.example.com

guidance

Choosing dsieve

Use dsieve to normalize and scope a domain list by level between discovery and probing. Reach for duplicut to deduplicate a wordlist while keeping order. Use anew to merge new findings into a running set. dsieve is the level-aware shaping step, not a deduplicator.

duplicut

Removes duplicates from a wordlist without sorting it. dsieve filters and extracts domains by subdomain level, a different shaping job.

anew

Appends only new lines to a file. A sibling utility for keeping a running set, not for level filtering.

faq

dsieve questions

Filter to level 2 with dsieve -if urls.txt -f 2. dsieve counts labels, so level 2 is the two-label apex like example.com and higher levels add subdomains. The output is the deduplicated set of root domains.

related

More Utilities tools

  1. cewl

    Spider a URL and return a wordlist for password crackers.

  2. dnsgen

    Wordlist and mined-word subdomain permutation.

  3. pup

    CSS selectors over HTML, the jq counterpart for markup.

  4. unfurl

    Extract chosen URL parts from stdin into clean line lists.

  5. whisper

    Speech to txt, vtt, srt, and json from an audio file or folder.

  6. youtube-transcript

    Public caption tracks to transcript.txt and results.jsonl.

Run dsieve yourself

A URL list feeds dsieve, which filters the domains down to the level you want and passes the scoped hosts to httpx so only live names land as output.

Open dsieve in the libraryBuild a workflow with it

Facts on this page come from the live Trickest tool library.