indicatif

indicatif is a Rust library for showing users progress in command-line applications, providing configurable progress bars, spinners, and basic terminal color support. It’s part of the console-rs family of crates (alongside console and dialoguer) and is one of the most widely depended-upon terminal UI crates in the Rust ecosystem, with over 184 million total downloads.

Beyond a single progress bar, indicatif supports MultiProgress for coordinating several concurrently rendered bars (e.g. per-file download progress), an iter() extension for wrapping any iterator with automatic progress tracking, and a rayon integration for progress on parallel iterators. Companion crates in the ecosystem — indicatif-log-bridge and tracing-indicatif — let it coexist cleanly with the log and tracing crates so log output doesn’t collide with an active progress bar’s rendering.

What You Get

• ProgressBar and ProgressStyle for single progress bars/spinners with customizable templates, characters, and colors
• MultiProgress for rendering several progress bars concurrently, e.g. one per parallel download or worker thread
• An iter() extension trait that wraps any Iterator to report progress automatically as it’s consumed
• Optional rayon feature for automatic progress tracking on parallel iterators
• Ecosystem integrations (indicatif-log-bridge, tracing-indicatif) so log/tracing output doesn’t corrupt active progress bar rendering

Common Use Cases

• Showing download/upload progress in CLI tools that transfer files over the network
• Displaying build or processing progress across many parallel tasks (e.g. compiling, testing, batch file processing)
• Wrapping a long-running iterator (like a directory walk or dataset scan) with a live progress bar via .progress()
• Building interactive CLI UX comparable to tools like cargo, yarn, or npm’s own progress output

Under The Hood

Architecture — The crate separates rendering concerns cleanly: progress_bar.rs (876 lines) exposes the public ProgressBar API, state.rs (884 lines) tracks position/length/timing state behind a shared, thread-safe handle, style.rs (1,184 lines) handles template parsing and rendering (spinners, bars, ETA/speed formatting), multi.rs (802 lines) coordinates multiple bars’ terminal positions via a shared draw_target.rs, and term_like.rs/in_memory.rs abstract the actual terminal so tests can render against an in-memory buffer instead of a real TTY.

Tech Stack — Pure Rust, built on the console crate (a sibling console-rs project) for terminal capability detection and ANSI styling, with optional integrations gated behind Cargo features for rayon (parallel iterators), tokio (async), improved_unicode (grapheme-aware width calculation), and in_memory (test rendering).

Code Quality — Tests (tests/render.rs, tests/multi-autodrop.rs) render against the in-memory terminal abstraction to assert exact byte-for-byte output, a strong pattern for a library whose entire job is precise terminal rendering. The crate ships 14+ runnable examples (download, multi-tree, rayon, tokio, log integration) that double as both documentation and de facto integration tests, and CI includes deny.toml-enforced dependency auditing.

API Design — The builder-style ProgressBar::new(len).with_style(...) API and template-string-based styling (e.g. {spinner} {msg} [{bar}] {pos}/{len}) make common cases quick to reach while still exposing enough low-level control (custom characters, tick strings, ETA formatting) for polished CLI UX. The iterator extension trait (.progress()) is a particularly low-friction entry point — wrapping an existing loop in a progress bar requires almost no code change.