claude-prompting-best-practices changedbuild-with-claude/prompt-engineering/claude-prompting-best-practices
Nearest release: v2.1.293, published an hour before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+9added
Lines−4removed
From line
4
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits23to this page, all time
The whole hunk
from line 4, old and new numbered
/
from line 4
44description: Comprehensive guide to prompt engineering techniques for Claude's latest models, covering clarity, examples, XML structuring, thinking, and agentic systems.
55---
66
7This is the reference for prompt engineering with current Claude models, including Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 5.5, Claude Sonnet 5, Claude Sonnet 4.6, and Claude Haiku 4.5. The page is organized in three parts:
7This is the reference for prompt engineering with current Claude models, including Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 5.5, Claude Sonnet 5, Claude Sonnet 4.6, Claude Haiku 5.5, and Claude Haiku 4.5. The page is organized in three parts:
88
99* **[Model-specific guidance](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/claude-prompting-best-practices#model-specific-guidance)** first: where a single model behaves differently and what to change in your prompt.
1010* **Techniques for all current models** after that: general principles, output and formatting, tool use, thinking, and agentic systems.
from line 11
1111* **Migration considerations** last, for prompts moving from earlier generations.
1212
1313<Tip>
14 For an overview of model capabilities, see the [models overview](https://platform.claude.com/docs/en/models/overview). For Claude Fable 5.1 capabilities and API changes, see [What's new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1). For Claude Fable 5 capabilities and API changes, see [Introducing Claude Fable 5 and Claude Mythos 5](https://platform.claude.com/docs/en/models/fable-5/introducing-claude-fable-5-and-claude-mythos-5). For migration guidance, see the [Migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide). For Claude Opus 5.5, see [What's new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5). For Claude Sonnet 5.5, see [What's new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5).
14 For an overview of model capabilities, see the [models overview](https://platform.claude.com/docs/en/models/overview). For Claude Fable 5.1 capabilities and API changes, see [What's new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1). For Claude Fable 5 capabilities and API changes, see [Introducing Claude Fable 5 and Claude Mythos 5](https://platform.claude.com/docs/en/models/fable-5/introducing-claude-fable-5-and-claude-mythos-5). For migration guidance, see the [Migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide). For Claude Opus 5.5, see [What's new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5). For Claude Sonnet 5.5, see [What's new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5). For Claude Haiku 5.5, see [What's new in Claude Haiku 5.5](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5).
1515</Tip>
1616
1717## Model-specific guidance
from line 27
2727| Claude Opus 5.5 | [Prompting Claude Opus 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5-5) | Differences from Claude Opus 5: effort calibration, prompts written for thinking disabled, user-facing progress updates, safeguard refusals, and tools for complex visual inputs. |
2828| Claude Opus 5 | [Prompting Claude Opus 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5) | Differences from prior Opus models: response length and verbosity, user-facing progress updates, written deliverable length, task scope and over-verification, subagent control, and self-correction. |
2929| Claude Opus 4.8 | [Prompting Claude Opus 4.8](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-4-8) | Response length, effort and thinking-depth calibration, tool use triggering, literal instruction following, subagent control, and design and frontend defaults. |
30| Claude Haiku 5.5 | [Prompting Claude Haiku 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-haiku-5-5) | Differences from Claude Haiku 4.5: effort levels, search, JSON output with your own tools, early stopping in long agent prompts, verification on coding tasks, mid-turn user messages, system prompt adherence in chatbots, and safeguard refusals. |
3031
3132## General principles
3233
from line 774
773774 ```
774775</CodeGroup>
775776
776If you are not using extended thinking, no changes are required. On Claude Opus 4.6 through Claude Opus 4.8 and Claude Sonnet 4.6, thinking is off when you omit the `thinking` parameter. On Claude Opus 5, Claude Sonnet 5.5, and Claude Sonnet 5, thinking is on by default when you omit the `thinking` parameter. On Claude Opus 5, you can disable it only at effort `high` or lower. On Claude Sonnet 5.5, the lowest thinking setting is `between_tools`, accepted at effort `high` or lower. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on, regardless of whether you set the `thinking` parameter.
777If you are not using extended thinking, no changes are required. On Claude Opus 4.6 through Claude Opus 4.8 and Claude Sonnet 4.6, thinking is off when you omit the `thinking` parameter. On Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, and Claude Haiku 5.5, thinking is on by default when you omit the `thinking` parameter. On Claude Opus 5 and Claude Haiku 5.5, you can disable it only at effort `high` or lower. On Claude Sonnet 5.5, the lowest thinking setting is `between_tools`, accepted at effort `high` or lower. On Claude Fable 5.1, Claude Mythos 5.1, Claude Fable 5, Claude Mythos 5, and Claude Opus 5.5, thinking is always on, regardless of whether you set the `thinking` parameter.
777778
778779* **Prefer general instructions over prescriptive steps.** A prompt like "think thoroughly" often produces better reasoning than a hand-written step-by-step plan. Claude's reasoning frequently exceeds what a human would prescribe.
779780* **Multishot examples work with thinking.** Worked examples in your prompt shape how Claude approaches similar problems in its own thinking blocks. Present each example as a problem, the method to apply, and the expected answer.
from line 1083
10821083
108310846. **Tune anti-laziness prompting:** If your prompts previously encouraged the model to be more thorough or use tools more aggressively, dial back that guidance. Claude 4.6 models are more proactive and may overtrigger on instructions that were needed for previous models.
10841085
10857. **Pass thinking blocks back unchanged and keep history append-only:** Append each assistant turn exactly as the API returned it, thinking blocks included. On Claude Fable 5.1, Claude Opus 5.5, and Claude Sonnet 5.5, [modifying the conversation before a thinking block](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation) results in an error, or in the block being dropped if you opt into that: editing earlier messages, rebuilding `system` or `tools`, or summarizing older turns in place between requests invalidates every later thinking block, so move those changes to mid-conversation system messages and server-side context management. See [Keep the conversation history append-only](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1#keep-the-conversation-history-append-only).
10867. **Pass thinking blocks back unchanged and keep history append-only:** Append each assistant turn exactly as the API returned it, thinking blocks included. On Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, and Claude Haiku 5.5, [modifying the conversation before a thinking block](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation) results in an error, or in the block being dropped if you opt into that: editing earlier messages, rebuilding `system` or `tools`, or summarizing older turns in place between requests invalidates every later thinking block, so move those changes to mid-conversation system messages and server-side context management. See [Keep the conversation history append-only](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-fable-5-1#keep-the-conversation-history-append-only).
10861087
10871088For detailed migration steps, see the [Migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide).
10881089
from line 1116
11151116
11161117 <Card title="Prompting Claude Opus 5" icon="terminal" href="https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5">
11171118 Behavioral differences and prompting patterns for Claude Opus 5, covering response verbosity, agentic narration, task scoping, subagent delegation, and self-correction.
1119 </Card>
1120
1121 <Card title="Prompting Claude Haiku 5.5" icon="terminal" href="https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-haiku-5-5">
1122 Behavioral differences and prompting patterns for Claude Haiku 5.5, covering effort, search, JSON output with your own tools, early stopping, coding verification, mid-turn user messages, system prompt adherence in chatbots, and safeguard refusals.
11181123 </Card>
11191124
11201125 <Card title="Prompt engineering overview" icon="edit" href="https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/overview">
No line in this hunk matches that.