URL filter syntax

Every filter on catchseo.com auction pages is encoded in the URL. URLs are stable, shareable, and indexed by Google. This page is the complete reference.

Equality

The simplest filter: field equals (or does not equal) a single value.

Syntax	Example	Meaning	Status
?f=value	`?tld=com`	equals	implemented
?f=!value	`?tld=!parked`	not equals	implemented

Lists (IN / NOT IN)

Match against multiple values at once. Use a comma to separate values.

Syntax	Example	Meaning	Status
?f=v1,v2,v3	`?tld=com,net,org`	in list (any of these values)	implemented
?f=!v1,!v2	`?tld=!parked,!squatted`	not in list (none of these values)	implemented

Mixing rule: all items in a list must have the same negation. Mixed lists like ?tld=!com,net are rejected.

Numeric ranges

Use a hyphen to separate the lower and upper bounds. Omit a bound to leave that side open.

Syntax	Example	Meaning	Status
?f=N-M	`?dr=50-100`	between N and M (inclusive both sides)	implemented
?f=N-	`?dr=50-`	at least N (open upper bound)	implemented
?f=-M	`?dr=-100`	at most M (open lower bound)	implemented

The >= and <= operators aren't part of the URL syntax — ranges always use the hyphen form (100-500).

Text matching

Use * as a wildcard for substring or prefix matching on string fields.

Syntax	Example	Meaning	Status
?f=sub	`?domain=shop`	contains substring	experimental
?f=!sub	`?domain=!xxx`	does not contain substring	experimental
?f=prefix*	`?domain=crypto*`	starts with prefix	implemented
?f=!prefix*	`?domain=!parked*`	does not start with prefix	implemented

ENDS WITH (?f=*suffix) is reserved syntax — Meilisearch doesn't support it yet. It will light up when they add the operator.

Existence / null / empty

Three distinct operators matching different "absence-like" states. Useful for power queries like "show me auctions without Ahrefs data yet."

Syntax	Example	Meaning	Status
?f=*	`?ahrefsData=*`	field key exists (any value, including null/empty)	implemented
?f=!*	`?ahrefsData=!*`	field key is entirely missing	implemented
?f=null	`?ahrefsData=null`	field key is present but value is null	implemented
?f=!null	`?ahrefsData=!null`	field key is present and value is not null	implemented
?f=empty	`?notes=empty`	field value is empty ("", [], or {})	implemented
?f=!empty	`?notes=!empty`	field value is not empty	implemented

The three are distinct:

!* (NOT EXISTS) — the field key is entirely missing from the document
null (IS NULL) — the field key is present but its value is literal null
empty (IS EMPTY) — the field key is present but its value is "", [], or {}

Sort & multi-sort

Sort by one or more columns. Use a dot to separate the column id from the direction. For multi-column sort, separate entries with a comma — the first entry is the primary sort, subsequent ones break ties.

Syntax	Example	Meaning	Status
?sort=col.asc	`?sort=godaddyData.auctionEndTime.asc`	sort ascending by one column	implemented
?sort=col.desc	`?sort=godaddyData.price.desc`	sort descending (nested-path safe)	implemented
?sort=col1.dir,col2.dir	`?sort=dr.desc,godaddyData.price.asc`	multi-column sort (primary, secondary, …)	implemented

Nested column paths work: the parser uses a last-dot rule, so godaddyData.price.desc correctly resolves to { id: "godaddyData.price", desc: true }. Any depth of nesting is fine.

Combining filters

Combine multiple filters by joining them with & — standard URL query string syntax. Filters across different fields are AND-joined.

/auctions?tld=com,net&dr=50-100&godaddyData.price=0-500&sort=godaddyData.auctionEndTime.desc

Reads as: TLD in (com, net) AND DR between 50 and 100 AND price between 0 and 500, sorted by auction end descending.

Cross-field OR is not expressible in the URL — filters across different fields always combine with AND.

Reserved / unsupported syntax

These patterns are intentionally not in the active grammar but are reserved at the parser level so adding them later won't break existing URLs.

Pattern	Why not
?f=>N or ?f=<M	Strict comparison. Use the hyphen form with an integer offset (?f=51- for > 50) — our filterable fields are all integers, so this is semantically equivalent and stays SEO-clean.
?f=>=N or ?f=<=M	Explicit inclusive comparison. The hyphen form (?f=N-, ?f=-M) is the canonical form.
?f=*suffix	ENDS WITH operator. Meilisearch doesn't support it yet; reserved in the grammar for the day they add it.
?f=N-M,P-Q	Disjoint ranges (union). Not currently supported; reserved syntax.
?f=~pattern	Regex matching. Postgres supports it but Meilisearch doesn't; reserved character.
?location=geo:lat,lng,radius	Geo-radius filtering. Reserved for the day we have geo data on auctions.
?q="<expression>"	Compound cross-field expressions ((dr>50 AND bl>100) OR …) aren't part of the URL syntax.

Bookmark, share, automate

Filters live entirely in the URL, and every filter combination has exactly one canonical address — so a bookmarked or shared link always reproduces the exact same view.

Want to keep a view without managing URLs? Save it as a Saved Search from the toolbar — and turn on alerts to get an email when new domains match it.