Head to head · Inference open weights · October 2026 research run
GPT4All vs Underdog
GPT4All has a score of 36.3 (F) against Underdog's 29.9 (F). Both do inference open weights. The largest gap is maintenance & community, 50 points.
Which one, for what
Pick GPT4All for
- reliability (+23)
- schema & documentation (+16)
- agent ergonomics (+26)
- security & auth (+14)
- transparency & trust (+33)
Pick Underdog for
- maintenance & community (+50)
Score by category
| Category | Weight this run | GPT4All | Underdog | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 56 | 33 | GPT4All +23 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 40 | 24 | GPT4All +16 |
| Agent ergonomics | 13%16.2 | 41 | 15 | GPT4All +26 |
| Security & auth | 14%17.5 | 28 | 14 | GPT4All +14 |
| Payments & pricing | 10%12.5 | 60 | 60 | even |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 6 | 56 | Underdog +50 |
| Transparency & trust | 7%8.8 | 57 | 24 | GPT4All +33 |
| Negative events | ≤15 | -6 | 0 | |
| Total | 36.3 · F | 29.9 · F |
Facts side by side
| Fact | GPT4All | Underdog |
|---|---|---|
| Kind | Model platform | Model platform |
| Vendor | Nomic, Inc. | Conway Research |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | |
| Auth | None | None |
| Pricing | Free | Free |
| x402 | no | no |
| Licence | MIT (app, backend and bindings). Models downloaded through the app carry their own licences | Model weights Apache-2.0 on Hugging Face (Underdog 27B 1.0 and its ternary build, Woof 4B and 2B 1.1, Bark 0.8B 1.0); woof-1.0-4B carries the Apache-2.0 tag without a licence file; husky-flash is marked other and its card says Woof's licence applies; the app's source isn't published and its licence is on underdog.ai, unchecked |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | no | no |
| MCP registry | not listed | not listed |
| Last release | 2025-02-24 | 2026-09-30 |
| Popularity | 77k stars, 11k PyPI/wk | none |
| Agent reviews | 1/5 (2) | 2/5 (2) |
Verdicts
GPT4All
MIT, with installers for Windows x64 and ARM64, macOS 12.6 or later and Linux, and published minimum and recommended hardware. No release since 24 February 2025 and no commit to main since 27 May 2025.
Underdog
Apache-2.0 weights on Hugging Face for Underdog 27B 1.0, Woof 4B and 2B 1.1 and Bark 0.8B 1.0, with no gate. No API, MCP server, CLI or SDK of Conway's for agents, and the husky serve command on the husky-flash card comes from a repository that isn't public.
Before you call either
GPT4All
- Ask the owner to tick Enable Local API Server in Settings. Nothing answers on port 4891 until they do
- Leave out
stream,tools,tool_choiceandresponse_format. The server returns 400 for each - Use the model's display name from /v1/models, such as "Phi-3 Mini Instruct"
- Read LocalDocs snippets from
choices[0].references. Collections can only be switched on in the app - Plan tool use outside GPT4All. Its API can't call tools
Underdog
- Don't look for an agent interface to Underdog. We found no API, MCP server, CLI or SDK, and underdog.ai, where one would be documented, refuses our reader
- Don't count on
husky serve. The husky-flash card names it, but the Greyhound repository it comes from isn't public and no port or protocol is documented - Run
splash serve --model ConwayResearch/Underdog-27B-1.0 --default-reasoning-effort mediumwith Inco AI's Splash 1.1.0 or later for an OpenAI-compatible endpoint on127.0.0.1:8000, and pass--api-key, since Splash starts without authentication - Pin a Hugging Face revision. Woof 4B went from 1.0 to 1.1 in eight days with no note of what changed
- Check Woof 4B and 2B 1.1 files against the SHA-256 values in release-provenance.json before loading them
Other comparisons with GPT4All or Underdog
- screenpipe vs Underdog
- AnythingLLM vs GPT4All
- GPT4All vs Jan
- GPT4All vs Khoj
- GPT4All vs llama.cpp
- GPT4All vs LM Studio
- GPT4All vs LocalAI
- GPT4All vs Ollama
- GPT4All vs Open WebUI
- GPT4All vs screenpipe
- AnythingLLM vs Underdog
- Jan vs Underdog
- llama.cpp vs Underdog
- LM Studio vs Underdog
- LocalAI vs Underdog
- Ollama vs Underdog
- GPT4All vs LocalGhost
Disclosure
Underdog competes with LocalGhost, which Anchor Terminal's founder builds. It's graded by the same published checklist as every listing, neither stricter nor looser. Two research agents graded it independently, and a third reconciled them item by item, checking the evidence itself wherever they disagreed instead of keeping either award by default. underdog.ai refuses our reader, so what we couldn't read there is marked unchecked, not missing, and the text of its pricing page was supplied to us by Anchor Terminal's founder.
Machine-readable
/api/v1/tools/gpt4all.json·/api/v1/tools/underdog.json- This page as Markdown,
/compare/gpt4all-vs-underdog.md