Claude Sonnet 4.5 vs Gemma 4 26B A4B

Anthropic · US  |  Google · US · Updated June 2026

Quick verdict

Pick Claude Sonnet 4.5 for agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch or computer use and gui automation (61.4% osworld at launch). Pick Gemma 4 26B A4B for fast, cheap inference from a sparse moe (3.8b active of 25.2b total) or near-31b-dense quality at a fraction of the compute and memory-bandwidth cost. Choose Gemma 4 26B A4B if you need self-hosting or data privacy; Claude Sonnet 4.5 if you want a managed API.

Claude Sonnet 4.5 (Anthropic) and Gemma 4 26B A4B (Google) are two of the models people most often weigh against each other in 2026. Claude Sonnet 4.5 is september 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. Gemma 4 26B A4B is an Apache-2.0 open MoE with 25.2B total but only 3.8B active parameters, delivering near-31B-dense quality at a fraction of the inference cost. They diverge most on price, context window and open vs. closed weights — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecClaude Sonnet 4.5Gemma 4 26B A4B
ProviderAnthropic (US) Google (US)
ReleasedSeptember 29, 2025 April 2, 2026
Context window200K (~300 pages) 256K (~393 pages)
Price (in/out)$3/$15 per 1M tokens $0.15/$0.6 per 1M tokens
Open weight?No — API only Yes — self-hostable
Modalitiestext, image, code text, image, video, code
SWE-Bench Verified77.2% Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch

Claude Sonnet 4.5

Claude Sonnet 4.5 lists agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch among its strengths; Gemma 4 26B A4B does not.

Computer use and GUI automation (61.4% OSWorld at launch)

Claude Sonnet 4.5

Claude Sonnet 4.5 lists computer use and GUI automation (61.4% OSWorld at launch) among its strengths; Gemma 4 26B A4B does not.

Long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks

Claude Sonnet 4.5

Claude Sonnet 4.5 lists long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks among its strengths; Gemma 4 26B A4B does not.

Fast, cheap inference from a sparse MoE (3.8B active of 25.2B total)

Gemma 4 26B A4B

At $0.15/$0.6 per 1M tokens it undercuts Claude Sonnet 4.5 ($3/$15 per 1M tokens), and that gap compounds at volume.

Near-31B-dense quality at a fraction of the compute and memory-bandwidth cost

Gemma 4 26B A4B

Its 256K window holds about 1.3× more than Claude Sonnet 4.5's 200K in a single prompt.

Strong reasoning and coding (88.3% AIME 2026 no-tools, 77.1% LiveCodeBench v6)

Gemma 4 26B A4B

An Apache-2.0 open MoE with 25.2B total but only 3.8B active parameters, delivering near-31B-dense quality at a fraction of the inference cost — and it runs cheaper at $0.15/$0.6 per 1M tokens.

Lowest cost at scale

Gemma 4 26B A4B

At $0.15/$0.6 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Gemma 4 26B A4B

Its 256K window is about 1.3× larger than Claude Sonnet 4.5's 200K, fitting roughly 393 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Gemma 4 26B A4B

At $0.15/$0.6 per 1M tokens it undercuts Claude Sonnet 4.5, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Gemma 4 26B A4B

Larger 256K window fits more in one prompt.

A team with data-privacy or self-hosting needs

Gemma 4 26B A4B

Open weights let you run it on your own hardware; Claude Sonnet 4.5 is API-only.

Anyone whose priority is agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch

Claude Sonnet 4.5

It is specifically built for that.

Anyone whose priority is fast, cheap inference from a sparse moe (3.8b active of 25.2b total)

Gemma 4 26B A4B

That is its strongest area.

Claude Sonnet 4.5: where it fits

September 2025's coding state of the art at $3/$15 — still supported, but 200K-capped and twice superseded. Released September 29, 2025 by Anthropic, it is built for agentic coding — 77.2% on SWE-Bench Verified, the best score any model had posted at its launch, computer use and GUI automation (61.4% OSWorld at launch), long-horizon autonomy — Anthropic reported 30+ hours of sustained focus on multi-step tasks, and tracking its own remaining token budget natively, which few models do.

Its trade-offs are real: superseded twice — Sonnet 4.6 and Sonnet 5 match or beat it at the same or lower price, capped at 200K since Anthropic retired its 1M beta in April 2026, while its successors ship 1M as standard, and missing the modern API surface: no adaptive thinking, no effort control, and half the max output of newer Sonnets. At $3 in / $15 out per million tokens, it sits in the mid price band.

Gemma 4 26B A4B: where it fits

An Apache-2.0 open MoE with 25.2B total but only 3.8B active parameters, delivering near-31B-dense quality at a fraction of the inference cost. Released April 2, 2026 by Google, it is built for fast, cheap inference from a sparse MoE (3.8B active of 25.2B total), near-31B-dense quality at a fraction of the compute and memory-bandwidth cost, strong reasoning and coding (88.3% AIME 2026 no-tools, 77.1% LiveCodeBench v6), and multimodal input (text/image, plus video processed as frames up to 60s) with native function calling.

Its trade-offs: all 25.2B parameters must be loaded into memory even though only 3.8B are active per token, and 256K context trails 1M-token frontier rivals, and this variant has no audio input (audio is E2B/E4B/12B only). At $0.15 in / $0.6 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

The defining split here is open vs. closed. Gemma 4 26B A4B gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. Claude Sonnet 4.5 gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.

Want both Claude Sonnet 4.5 and Gemma 4 26B A4B without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Claude Sonnet 4.5 or Gemma 4 26B A4B better for coding?

Public SWE-Bench figures are not available for Gemma 4 26B A4B, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 4.5 leans toward agentic coding — 77.2% on swe-bench verified, the best score any model had posted at its launch while Gemma 4 26B A4B leans toward fast, cheap inference from a sparse moe (3.8b active of 25.2b total), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Claude Sonnet 4.5 or Gemma 4 26B A4B?

Gemma 4 26B A4B is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while Claude Sonnet 4.5 is API-metered at $3/$15 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.

Which has the bigger context window?

Gemma 4 26B A4B — 256K vs 200K, about 1.3× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Claude Sonnet 4.5 and Gemma 4 26B A4B together?

Yes — a multi-model platform like LumiChats gives you Claude Sonnet 4.5, Gemma 4 26B A4B and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Claude Sonnet 4.5 or Gemma 4 26B A4B?

Gemma 4 26B A4B — released April 2, 2026, about 6 months after Claude Sonnet 4.5.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.