# xAI vs Relace

> Grok is a general closed model that can plan and write code. Relace supplies small, fast models for the apply, search and compaction steps around it.

Canonical: https://www.subconscious.dev/compare/xai-vs-relace · By The Subconscious Team · Updated September 30, 2026

## How they compare

Relace builds tools, not a general model. Its relace-apply-3 merges a lazy edit snippet into the original file at about 10,000 tokens per second with 128K tokens of input and output, its agentic search explores large codebases in parallel, and a compaction model runs at 50,000 tokens per second. Relace says the apply step runs over 3x faster and cheaper than having the big model rewrite the file. xAI supplies that big model: Grok 4.6, or grok-build for coding, with Grok 4.20 offering 1M context.

In a coding agent the two fit together. Grok plans and writes the edit, Relace applies it, and Relace's search and compaction keep the context Grok sees small, which matters because xAI bills the whole request at double once a prompt hits 200K tokens. Relace returns an error past 128K tokens, so very large files need a fallback, and Grok 4.20's 1M window can play that role. Relace also offers self-hosting for enterprises that keep code in-house, which xAI does not.

## What each one does

### xAI

xAI sells the Grok models through its own API. Grok 4.6 is the current flagship and xAI tells developers to use it for everything outside audio, image and video, code included. It has a 500K context window and costs $2 in and $6 out per million tokens under 200K prompt tokens. Older Grok 4.20 and 4.3 models keep a 1M window at $1.25 in and $2.50 out, which is aggressive for that capability class.

### Relace

Relace trains small, fast models that act as tools for coding agents. Its best-known product is Instant Apply: a frontier model writes a lazy edit snippet, and relace-apply-3 merges it into the original file at about 10,000 tokens per second with 128K tokens of input and output. Relace says this runs over 3x faster and cheaper than having the big model rewrite the file. It exposes both a REST endpoint and an OpenAI-compatible one, and the model is also listed on OpenRouter.

## Which is best, and when

### Choose xAI for

- The reasoning model that writes code edits
- Large-file fallback with 1M context on Grok 4.20
- Agents that mix coding with live data lookups

### Choose Relace for

- Fast merges of lazy edits into files
- Parallel search over large repositories
- Self-hosted code tooling for in-house repos

## At a glance

| Attribute | xAI | Relace |
|---|---|---|
| Model access | Closed | Specialist models |
| Flagship models | Grok 4.6, Grok 4.20, grok-build | relace-apply-3, agentic search |
| Speed | ~54 tok/s on Grok 4.6 | ~10,000 tok/s apply |
| Price | $2 in, $6 out (Grok 4.6); 2x past 200K | 3x+ cheaper than full rewrites |
| Customization | - | - |
| Deployment | First-party API | Hosted API or self-hosted |
| Long context | 500K (4.6), 1M (4.20, 4.3) | 128K max |

## FAQ

### What is the difference between xAI and Relace?

Grok is a general closed model that can plan and write code. Relace supplies small, fast models for the apply, search and compaction steps around it.

### When should I choose xAI over Relace?

The reasoning model that writes code edits; Large-file fallback with 1M context on Grok 4.20; Agents that mix coding with live data lookups.

### When should I choose Relace over xAI?

Fast merges of lazy edits into files; Parallel search over large repositories; Self-hosted code tooling for in-house repos.

### Is xAI or Relace cheaper?

xAI: $2 in, $6 out (Grok 4.6); 2x past 200K. Relace: 3x+ cheaper than full rewrites. The cheaper choice depends on the model and workload.

### Which has more context, xAI or Relace?

xAI: 500K (4.6), 1M (4.20, 4.3). Relace: 128K max.

## Running long-horizon agents?

If your agents run past 200K tokens, compare both against Subconscious: [Subconscious vs xAI](https://www.subconscious.dev/compare/subconscious-vs-xai.md), [Subconscious vs Relace](https://www.subconscious.dev/compare/subconscious-vs-relace.md).

Full profiles: [xAI](https://www.subconscious.dev/providers/xai.md), [Relace](https://www.subconscious.dev/providers/relace.md).