head to head · open source
vllm vs langtest
vllm has 92,055 GitHub stars, 22,349 forks, 7,953 open issues and last shipped today. langtest has 560 stars, 53 forks, 6 open issues and last shipped 21 days ago. vllm leads on adoption by 16,338% (92,055 vs 560 stars). vllm is written in Python under Apache-2.0; langtest is written in Python under Apache-2.0. vllm has attracted 24% as many forks as stars, langtest 9%. vllm was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (llm), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| vllm | langtest | |
|---|---|---|
| GitHub stars | ★ 92K | ★ 560 |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Python | Python |
| Last push | 2026-09-18 | 2026-08-28 |
| Forks | ⑂ 22K | ⑂ 53 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick vllm if
- You weight community size — 92K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick langtest if
- You want the langtest feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Python
- You evaluated both and langtest fits your workflow better
About vllm
vLLM is a high throughput, memory efficient Python library for LLM inference and serving, built for ML engineers and platform teams who need to run open weight models on their own hardware at production scale.
About langtest
LangTest: Deliver Safe & Effective Language Models Project's Website • Key Features • How To Use • Benchmark Datasets • Community Support • Contributing • Mission • License Project's Website Take a look at our official page for user documentation and examples: langtest.org Key Features Generate and execute more than 60 distinct types of tests only with 1 line of code Test all aspects of model quality: robustness, bias, representation, fairness and accuracy. Automatically augment training data based on test results (for select models) Support for popular NLP frameworks for NER, Translation and Text Classifcation…
read the full langtest overview →
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Frequently asked questions
Is vllm or langtest more popular?
vllm has 92,055 GitHub stars and langtest has 560. vllm has the larger community by that measure.
Are vllm and langtest free?
Both are open source. vllm is licensed under Apache-2.0 and langtest under Apache-2.0. Neither carries a licence fee.
What is the difference between vllm and langtest?
vllm is written in Python and langtest in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, vllm or langtest?
Choose vllm if you want the larger community (92,055 stars) or its Apache-2.0 licence terms. Choose langtest if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.