Compare
Same hardware, close to the same speed
On the same GPUs as stock vLLM, SGLang or Ollama, kLLM adds a degree of privacy protection, and measured sealed throughput is close to plain serving on the same engine. kLLM runs SGLang and vLLM unchanged, so the comparison is a question of what the sealing layer adds and what it costs.
What it costs
Measured against plain serving on the same engine and GPU
Plain serving here is the unsealed checkpoint on the same stock engine and the same GPU. kLLM has not published a measurement against Ollama.
Served with --key, sealed throughput was never more than 0.3% below plain
Output throughput at concurrency 16, tok/s · plain, perm, orth · one NVIDIA A40 48 GB, bf16, 1024 input / 128 output tokens
0.3%
Largest measured drop in sealed output throughput at concurrency 16, keyed serving.
98.0 ms to 105.2 ms
Median time to first token at concurrency 1, Qwen3-1.7B on SGLang 0.5.21 (perm).
7%
Throughput cost of client-keyed mode under vLLM at concurrency 16 (1036 to 963 tok/s).
Conditions: One NVIDIA A40 48 GB; SGLang 0.5.21 or vLLM 0.31.0; bf16; 1024 input and 128 output tokens; GPU shared with another tenant's light job; single runs, no variance reported.
What it adds
kLLM, stock engines and Ollama
The comparison is limited to the aspects listed. Descriptions of other projects summarize their public documentation and may change.
| kLLM | Stock vLLM or SGLang | Ollama | |
|---|---|---|---|
| Inference engine | SGLang or vLLM, unmodified and not forked | The engine itself | Its own runtime |
| Model library with name:tag aliases | Yes, for example qwen3:8b; each tag pins an upstream revision | No; serves Hugging Face repositories and local paths | Yes |
| Pull and run | kllm pull, kllm run | One serve command per model | ollama pull, ollama run |
| OpenAI-compatible API | Yes, through the engine | Yes | Yes |
| Batching, tensor parallelism, CUDA graphs | Those of the engine, unchanged on sealed checkpoints | Yes | Not compared |
| Weights sealed under a key | Yes, for architectures with a validated implementation | No | No |
| Weights at rest | Locked by default: encrypted in place under the key, and unlocked on the machine that runs the model | As distributed | As distributed |
| Pre-sealed models | Official sealed models rolling out on Hugging Face, each under its own model key | No | No |
| Check a sealed model against its public base | kllm verify, with the model key: seals the base again and compares tensor by tensor | Not applicable | Not applicable |
| Prompts as received by the serving host | Token ids under the vocabulary permutation in client-keyed mode; not ciphertext | Plain text | Plain text |
| GPU memory of the serving host | Not protected; user text reduces to a substitution cipher over tokens | Not protected | Not protected |
| Platforms | Linux with an NVIDIA GPU; macOS and Windows installers planned | Primarily Linux with GPUs | macOS, Windows and Linux |
What it does not claim
Not a confidential GPU
kLLM does not claim the security of a confidential GPU. A confidential VM with an ordinary GPU does not protect GPU memory, and no part of kLLM is presented as equivalent to a confidential-GPU service.
Outside a confidential VM, kllm serve --key is a development mode with no protection from the host.
Disaggregated serving with confidential GPUs
Combined with confidential GPUs, transformed tensors can cross nodes without an extra encryption step. This is a design target for disaggregated serving, not a feature of the current release.
Planned
Planned for the local workflow
These items are design work and are not available in the current release.
| Item | Scope |
|---|---|
| Resident daemon on 127.0.0.1:11400 | One endpoint that routes OpenAI requests by model, with keep-alive and admission control |
| Ollama-compatible API | /api/chat and /api/generate |
| Local web console and Modelfile-style recipes | Browser management and declarative model recipes |
| Installers and packages | pip install kllm with the first tagged release; installers for macOS and Windows; published container images |