Time-To-First-Token (TTFT) measures the latency between a user sending a message and the first visible word appearing in the chat window.
Time-To-First-Token (TTFT) is a performance metric measuring the latency from initial user request dispatch to the arrival and display of the very first generated token.
In conversational interfaces, users perceive responsiveness based on how fast text begins typing out, not when the full paragraph finishes.
TTFT includes vector retrieval time, network roundtrips, prompt assembly, and initial model inference latency.
SiteMind achieves a sub-800ms TTFT by running hybrid PostgreSQL vector search in <45ms and streaming tokens immediately via Gemini Flash-Lite over Server-Sent Events.
Estimate support savings, token counts, or test prompt injection security guardrails with our zero-cost sandboxes.
Related Technical Concepts
Server-Sent Events (SSE Streaming)
Server-Sent Events (SSE) stream AI tokens continuously over a single HTTP connection, giving visitors real-time, typewriter-style responses.
Shadow DOM CSS Isolation
Shadow DOM encapsulates a chat widget’s HTML and CSS in a private tree, preventing host website styles from breaking the chatbot’s layout.
Context Window Limits
The context window is the maximum number of tokens an LLM can read and process in a single conversation turn, including system instructions, knowledge, and history.
Crawl your domain in 2 minutes, get instant grounded answers, and see your deflection rates.