Haiku 4.5 on GitHub Copilot: Code Faster, Spend Less

Imagine your AI coding assistant responding the instant you finish typing. No more lag, no more waiting—just seamless, real-time help that feels like a natural extension of your thoughts. That’s the promise of Anthropic’s new Claude Haiku 4.5, now Generally Available (GA) in GitHub Copilot. It’s not just another update; it’s a fundamental shift in developer experience.

Anthropic positions Claude Haiku 4.5 as delivering near-Sonnet 4 coding performance at one-third the price and more than twice the speed; a partner quote on Anthropic’s launch page cites ‘up to 4–5× faster than Sonnet 4.5.’

But is it powerful enough for your daily work? How much cheaper is it really inside Copilot? And most importantly, when should you use this new speedster versus its bigger, more powerful siblings?

The Key Takeaways

• Blazing fast: Optimized for low latency. Anthropic: >2× faster vs Sonnet 4; partner quote: up to 4–5× vs Sonnet 4.5 (testimonial; not a universal benchmark).
• Seriously cheap in Copilot: 0.33× multiplier (≈3× more premium-metered requests vs 1× models).
• Right tool for daily tasks: GitHub recommends it for “fast help with simple or repetitive tasks.” (GitHub model guide)
• Know its limits: For deep reasoning / multi-file refactors / complex debugging, use Sonnet 4.5 or Opus 4.1. Agent mode: Not available on Haiku 4.5 (see GitHub’s comparison).

What is Claude Haiku 4.5?

Claude Haiku 4.5 is the latest AI model from Anthropic, specifically engineered to be extremely fast and cost-effective. As the “small” model in the Claude 4.5 family, it stands out for its combination of high intelligence and remarkable speed. Anthropic calls Haiku 4.5 its fastest, most cost-efficient model, matching Sonnet 4 on key coding tasks at ⅓ the price.

At its core, Anthropic Haiku 4.5 is designed to deliver near-frontier performance. This means it provides a level of coding and reasoning capability that was considered state-of-the-art only a few months ago. Specifically, it offers similar coding performance to the earlier Claude Sonnet 4 model but at a fraction of the price and with more than double the speed.

At A Glance

• Status in Copilot: GA
• Multiplier (paid plans): 0.33× (Sonnet 4/4.5 1×, Opus 4.1 10×)
• Agent mode: Not available on Haiku 4.5
• API price: $1/M in, $5/M out
• Where to switch: Chat/Completions model picker (GitHub.com, VS Code, JetBrains)
• Auto model selection (VS Code): 10% multiplier discount for paid plans.

This focus on efficiency makes the Claude 4.5 small model a practical choice for developers and businesses, democratizing access to high-quality AI without the high cost and latency typically associated with top-tier models.

The Need for Speed in Your Editor

Slow AI assistants break your concentration. Waiting even a second for a suggestion can pull you out of your workflow and disrupt your focus. This is where Claude Haiku 4.5 truly excels. It’s a shockingly fast model designed to eliminate that frustrating lag, making your interaction with GitHub Copilot feel seamless and immediate.

The goal is to enable real-time dev workflows. Generating regexes, unit-test stubs, or single-file refactors, where the AI keeps up with your pace of thought. This low-latency performance transforms how you use your coding assistant for everyday tasks.

This responsiveness makes the AI feel less like a separate tool and more like an integrated part of your editor. GitHub’s model guide groups Haiku 4.5 under fast help for simple or repetitive tasks.

How Haiku 4.5 Saves You Money

Claude Haiku 4.5 was designed from the ground up to be a fast & cheap LLM. For developers using the API directly, the Haiku 4.5 pricing is highly competitive at just $1 per million input tokens and $5 per million output tokens.

However, the real savings for developers come from how it’s integrated into GitHub Copilot. Instead of paying per token, Copilot measures usage in “premium requests.” In Copilot, Haiku 4.5 = 0.33×, Sonnet 4/4.5 = 1×, Opus 4.1 = 10×; a 300-request allowance yields ~900 Haiku prompts vs 300 on Sonnet. This low multiplier allows you to optimize your premium request burn significantly.

Using Auto model selection in VS Code gives paid users an additional 10% multiplier discount (e.g., Sonnet 4.5 is billed at 0.9×).

Your New Go-To for Daily Coding Tasks

While more powerful models are great for complex problems, the bulk of a developer’s day is often spent on smaller, more routine activities. This is where Haiku 4.5’s coding performance is most valuable. It provides high-quality, accurate results for the everyday. Tasks that can slow you down, acting as a reliable assistant for high-volume work.

It is the perfect tool for clearing your plate of common development chores, including:

• Repetitive coding tasks: Automating simple but time-consuming jobs like data mapping or API client generation.
• Boilerplate generation: Instantly creating file structures, class definitions, or function skeletons so you can start coding faster.
• Code documentation: Writing clear and concise docstrings or comments for your functions and classes.
• Unit test stubs: Quickly generating the framework for tests, letting you focus on writing the actual logic.
• Regex generation: Crafting complex regular expressions from a simple natural language description.
• Small refactors: Handling simple code cleanup, such as renaming variables or extracting a method, across a single file.

By offloading these responsibilities to Haiku 4.5, you can reserve your mental energy for more challenging architectural and logical problems. Its speed and efficiency make it the ideal default choice, turning tedious work into a quick conversation with your AI assistant.

Knowing When to Upgrade to a Bigger Model

While Haiku 4.5 is the new default for speed, it is essential to recognize its limits. GitHub’s comparison page recommends Haiku 4.5 for small/quick edits and larger models for deep reasoning/multi-file work. Its design prioritizes quick responses for well-defined tasks. Although it can struggle with problems that require extensive context or multi-step logic.

Consider upgrading from Haiku 4.5 in these situations:

• For Complex Logic and Refactoring: When you need to refactor code across several files or design a new, complex algorithm, the Haiku 4.5 vs Sonnet 4.5 comparison becomes clear. You need a model with Sonnet 4.5’s deep reasoning capabilities to maintain context and understand the broader impact of your changes.
• For the Toughest Bugs: If you’re tackling a mysterious bug with no obvious cause, you need a model built for advanced analysis. This is a job for Opus 4.1’s complex debugging power, which can trace logic through layers of code.
• For High-Level Architecture: When comparing Haiku 4.5 vs GPT-5 or other top-tier models, the larger models are better suited for architectural planning and designing entire systems from scratch.
• When You Need Autonomous Help: A critical limitation is that Agent mode is not available for Haiku 4.5. If you need the AI to independently plan and execute changes across your project, you must switch to a model like Sonnet 4.5 or GPT-5.

The primary trade-off is speed versus reasoning depth. For tasks that span multiple files, involve complex architectural decisions, or require understanding a large, intricate codebase, you should switch to a larger model.

How to Get Started with Haiku 4.5 in Copilot

Getting started with Claude Haiku 4.5 is simple, as it is now Generally Available (GA) in GitHub Copilot. This means it’s a standard, fully supported model in Copilot that you can select and use right away in your favorite editor.

Here’s a quick guide on how to switch (you can find more details in the GitHub Docs):

• Change Chat model (GitHub.com / VS Code / JetBrains): follow “Changing the AI model for Copilot Chat.” (GitHub Docs)
• Change completion model (VS Code/JetBrains): see “Changing the AI model for code completion.”

This functionality is available across all platforms with IDE support, including VS Code and the JetBrains suite, making it accessible no matter where you code.

What This Means for Teams and Budgets

The introduction of Claude Haiku 4.5 fundamentally changes the financial equation for integrating AI into development workflows. For managers and team leads, its primary benefit is the significant reduction in the effective cost per developer. Because of its low multiplier, teams can get roughly three times the usage from their existing GitHub Copilot allowances, making powerful AI assistance more accessible than ever.

This efficiency is a game-changer for budget-conscious deployments. Organizations can now scale AI across orgs with greater confidence, knowing that the costs associated with metered Copilot usage will be more predictable and manageable. Developers are empowered to use the tool generously for everyday tasks without the constant concern of quickly exhausting their premium request limits.

Ultimately, Haiku 4.5 directly lowers the total cost of ownership (TCO) for LLMs within an enterprise setting. It provides a sustainable path for teams to adopt a high-speed AI assistant, ensuring a strong return on investment by boosting productivity without inflating the budget.

Závěr

Claude Haiku 4.5 isn’t just another model in a dropdown menu; it’s a game-changer for daily productivity within GitHub Copilot. By offering blazing speed at an incredibly efficient price point, it establishes itself as the new default choice for the vast majority of coding tasks. It successfully solves the problem of AI latency. The interaction feel instant and keeping developers in a state of flow.

This allows developers to use their AI assistant more freely for everyday work. From writing documentation to generating boilerplate code. It also encourages a smarter workflow, where the more powerful and expensive models like Sonnet and Opus are reserved for the truly complex challenges where their deep reasoning is essential.

For fast, fluid, and frugal AI assistance, Haiku 4.5 has arrived, and your development workflow will never be the same.