Tab completion
Inline code suggestion that appears as ghost text and accepts on Tab. The original AI-assist UX, popularised by GitHub Copilot in 2021. Distinct from chat, edit, and agent modes which involve multi-turn interaction.
Background
Tab completion is the lowest-friction AI surface in coding tools. The model predicts the next several tokens or lines and renders them as inline ghost text; pressing Tab accepts. Latency must stay under ~300 ms for the UX to feel natural, which constrains model size — providers run distilled or smaller specialist models for this surface. As agentic modes mature, tab completion remains the most-used feature by line count across all AI coding tools.
Tools that use it
- 01→Cursor
VS Code-based, agent-first coding environment — since Cursor 3.0 the default surface is an Agents Window, not an editor.
- 02→Tabnine
Enterprise AI code completion with private models, zero data retention, and on-prem deployment options.
- 03→Codeium
Free AI code completion and chat across 70+ IDEs, with enterprise self-hosting available.
- 04→GitHub Copilot
GitHub's AI pair programmer with chat, inline completions, and agent mode across major IDEs.