AI Models / Use Cases / Summarisation

Best AI Models for Summarisation

Effective summarisation requires more than shortening text - it demands identifying what is genuinely important, preserving key nuance, and structuring the output for its intended use. For long documents, large context windows are essential: models that truncate input or hallucinate information they did not actually process are actively counterproductive.

Accuracy and completeness of key information Context window size for long document handling Structured output formats (bullets, sections) Reduction ratio without information loss

Top AI models for Summarisation

Ranked by real-world performance on summarisation tasks - pricing, context windows, and strengths for each.

1

Claude 4 Opus

text 200K tokens context

The flagship model, focused on deep reasoning, large-scale coding and sustained multi-step agentic workflows.

From $15 / 1M tokens View model
2

GPT-5.5

text 1M tokens context

OpenAI's smartest and most capable model yet for agentic coding, knowledge work, and computer use, delivering a new class of intelligence at GPT-5.4 latency.

From $5 / 1M tokens View model
3

GPT-5.4

text 1.1M tokens context

OpenAI's frontier model for complex professional work with best intelligence at scale for agentic, coding, and professional workflows.

From $2.5 / 1M tokens View model
4

Claude 4 Sonnet

text 1M tokens context

A balanced-hybrid reasoning model tuned for everyday assistant and high-volume tasks.

From $3 / 1M tokens View model
What to look for

Evaluation criteria for Summarisation

The four factors that matter most when choosing an AI model for summarisation tasks.

Accuracy and completeness of key information

Context window size for long document handling

Structured output formats (bullets, sections)

Reduction ratio without information loss

Appaca

Build Summarisation tools with the right model

Appaca is the AI workspace for operators. Build internal tools and AI co-workers powered by any of these models - connected to your real data and ready for your whole team. No code, no deployment.

Build summarisation tools instantly

Tell the Appaca agent the internal tool you need and it builds a working app powered by the model you choose for summarisation. No code, no API keys, no deployment.

Connected to your real data

Connect Slack, Notion, Google Sheets, Airtable, and more, plus a built-in database - so your AI tools work with your team's real context instead of generic answers.

Automated for the whole team

Schedule tools to run on autopilot - daily digests, weekly reports, real-time triggers - and share them with your whole team from one workspace.

Describe it, and it's built

Tell the Appaca agent what your team needs and it builds a working app powered by the model you choose - connected to the tools you already use.

SlackGoogle SheetsGoogle DriveGoogle CalendarAirtableNotionWhatsappHubspot
Chat to app Appaca app builder
Other use cases

Explore more use cases

Top-ranked AI models for other common business tasks.

FAQs

Which LLM is best for document summarisation in 2026?

Gemini 2.5 Pro and Claude 4 Opus are the top summarisation LLMs in 2026. Gemini 2.5 Pro handles the longest documents thanks to its 1M token context window, making it ideal for lengthy reports, legal documents, and multi-chapter texts. Claude 4 Opus produces the highest-quality summaries for complex documents where nuance and accuracy matter most.

Can an LLM accurately summarise a 100-page report?

Yes, with a large enough context window. Gemini 2.5 Pro and Claude 4 Opus can ingest a 100-page document (roughly 75,000-100,000 tokens) in a single pass. Shorter-context models require chunking and hierarchical summarisation, which risks losing connections between sections. For the most accurate summaries of long documents, use a model with at least 200K token context.

Which AI model has the largest context window for summarising long documents?

Both Gemini 2.5 Pro and Claude 4 Opus offer 1M token context windows - equivalent to roughly 750,000 words or about 1,500 pages. For standard summarisation tasks up to 50 pages, GPT-5.5 (128K context) and Claude 4 Sonnet (200K context) are also excellent choices with faster processing times.

Is Claude or GPT better for meeting transcript and call summarisation?

Claude 4 Sonnet is the best choice for meeting and call summarisation. It produces natural, easy-to-read summaries that capture key decisions, action items, and tone - while filtering out filler and tangential conversation. GPT-5.4 is also strong and tends to produce more structured summaries with clear action item formatting.

How do I automatically summarise large volumes of documents?

Build a document summarisation pipeline on Appaca: connect your document source (email, cloud storage, CRM), configure your summarisation prompt (length, format, focus areas), and route outputs to your team's preferred channel. For document collections, batch-process with Gemini 2.5 Flash for cost efficiency, reserving premium models for high-priority documents.

Build AI tools for Summarisation

Describe the summarisation tool your team needs and get a working app powered by the right model - with a built-in database, team access, and integrations. No code, no deployment.