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lobstr vs webmockr

A side-by-side editorial comparison of lobstr and webmockr — release velocity, themes, recent moves, and the top alternatives to consider.

lobstr vs webmockr: at a glance

Featurelobstrwebmockr
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesr-lib, introspection, memory, c-apihttp-mocking, testing, httr2, ropensci
Last editorial update5h ago1h ago
WebsiteVisit →Visit →

What is lobstr?

R's object inspector is losing its view of the internals as CRAN closes off the private C API.

lobstr exposes R's internal object representation — sizes, addresses, reference counts, abstract syntax trees. Its two most recent releases are both driven by R's move to a restricted public C API: 1.1.3 stopped reporting a vector's truelength and reworked the reference indicator into refs:n, and 1.2.0 changed what sxp(expand = "environment") shows in order to stay compliant. 1.2.0 also adds src() for exploring srcref objects.

Read the full lobstr trajectory →

What is webmockr?

The stubbing library added httr2 support, then spent a year cutting itself free of everything else

webmockr intercepts HTTP requests in R tests and returns stubbed responses, and since 1.0.0 it covers all three clients that matter — httr, httr2 and crul. The releases through 2025 have been about shedding dependencies: internal R6 classes unexported in 2.1.0, crul demoted from Imports to Suggests in the same release, and the mutual dependency with vcr severed in 2.2.0. The package now installs and runs without pulling in the rest of the rOpenSci HTTP stack.

Read the full webmockr trajectory →

lobstr vs webmockr: editorial side-by-side

L
lobstr
ANALYTICS
0.0

R's object inspector is losing its view of the internals as CRAN closes off the private C API.

◆ Current state

lobstr exposes R's internal object representation — sizes, addresses, reference counts, abstract syntax trees. Its two most recent releases are both driven by R's move to a restricted public C API: 1.1.3 stopped reporting a vector's truelength and reworked the reference indicator into refs:n, and 1.2.0 changed what sxp(expand = "environment") shows in order to stay compliant. 1.2.0 also adds src() for exploring srcref objects.

◆ Where it's heading

The package is being rebuilt inside a shrinking window of what R permits. Each release trades some introspection depth for API conformance while trying to keep the diagnostic value intact — showing promise expressions instead of internal frame structures, replacing named with a documented refs scale. Where the constraint does not bite, development continues normally: src() is genuinely new, and the environment-binding fixes remove long-standing errors on for-loop and immediate bindings.

◆ Prediction

Expect further conformance work, since the notes describe it as ongoing, with any remaining non-API-dependent readouts either reworked or dropped as R tightens further.

W
webmockr
ANALYTICS
0.0

The stubbing library added httr2 support, then spent a year cutting itself free of everything else

◆ Current state

webmockr intercepts HTTP requests in R tests and returns stubbed responses, and since 1.0.0 it covers all three clients that matter — httr, httr2 and crul. The releases through 2025 have been about shedding dependencies: internal R6 classes unexported in 2.1.0, crul demoted from Imports to Suggests in the same release, and the mutual dependency with vcr severed in 2.2.0. The package now installs and runs without pulling in the rest of the rOpenSci HTTP stack.

◆ Where it's heading

Two arcs run in sequence. The first is coverage — multiple queued responses in 0.7.0, basic auth mocking, async through crul, then httr2 — building out what can be stubbed. The second, starting with 2.0.0, is correctness and independence: stubs are now deleted if an error occurs mid-construction rather than lingering half-built, partial matching arrives for bodies and queries, and the dependency graph is pruned release by release. The 2.2.0 split from vcr landed within a minute of crul's release taking mocking control into its own clients.

◆ Prediction

RequestPattern is documented as still exported in 2.1.0 but slated for removal, so the next major release is where that lands. Expect continued dependency pruning rather than new client support — the three clients that exist are already covered.

Alternatives to lobstr and webmockr

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either lobstr or webmockr.

See all lobstr alternatives → · See all webmockr alternatives →

Recent activity from lobstr and webmockr

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 5mo agolobstrNew src() for srcrefs; environment bindings stop erroring
  2. 9mo agolobstrtruelength reporting dropped for public C API compliance
  3. 1y agowebmockrvcr dependency severed
  4. 1y agowebmockrInternal classes unexported; crul becomes an optional dependency
  5. 1y agowebmockrFailed stub construction cleans up; partial matching extends to bodies and queries
  6. 2y agowebmockrhttr2 joins httr and crul as a supported client
  7. 3y agowebmockrQueued responses, body matching and integer status codes fixed
  8. 3y agowebmockrRegex URI matching fixed
  9. 4y agolobstrMoves to cpp11, relicensed MIT, adds experimental tree()
  10. 7y agolobstrPROTECT error fixed
  11. 7y agolobstrALTREP sizes computed correctly; obj_addr() stops side-effecting

Frequently asked questions

What is the difference between lobstr and webmockr?

They serve adjacent needs but don't currently overlap on shipped themes. lobstr and webmockr are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is lobstr better than webmockr?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. lobstr and webmockr are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to lobstr?

Top lobstr alternatives in Analytics are ranked by recent ship velocity. Browse the "lobstr alternatives" section above for the current picks, or visit /alternatives/lobstr for the full list with editorial commentary on each.

What are the best alternatives to webmockr?

Top webmockr alternatives in Analytics are ranked by recent ship velocity. Browse the "webmockr alternatives" section above for the current picks, or visit /alternatives/webmockr for the full list with editorial commentary on each.