GLM-5.3 vs GPT-6.1 Sol vs Muse Spark 1.2

It is close. Our weighted score puts them within 1 points (GPT-6.1 Sol 72/100, Muse Spark 1.2 71/100, GLM-5.3 63/100), so choose by what matters most for your work: GPT-6.1 Sol for raw capability and Muse Spark 1.2 on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Muse Spark 1.2 is cheaper at $1.25 input / $4.25 output per million tokens (official Meta API price). GLM-5.3 costs $1.40 input / $4.40 output per million tokens (official Z.AI API price); GPT-6.1 Sol costs $2.00 input / $10.00 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $2.00 per million tokens for Muse Spark 1.2 versus $2.15 for GLM-5.3 (1.1× as much) and $4.00 for GPT-6.1 Sol (2× as much).

GPT-6.1 Sol scores higher on the Capabilities Index (ECI): GPT-6.1 Sol 167.8 (#4 of 165), GLM-5.3 156.2 (#33 of 165) and Muse Spark 1.2 155.2 (#38 of 165). Their confidence ranges do not overlap (164.3–172.5 vs 154.3–158.5), so the gap is a real one. On individual benchmarks: SimpleQA Verified — GPT-6.1 Sol 73.9%, Muse Spark 1.2 60.3%, GLM-5.3 41.0%.

There are no published SWE-bench Verified results for GLM-5.3, GPT-6.1 Sol and Muse Spark 1.2 yet, so there is no like-for-like coding score. On overall capability, GPT-6.1 Sol leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

GPT-6.1 Sol and Muse Spark 1.2 have the largest context windows (1,050,000 and 1,048,576 tokens), against 1,000,000 for GLM-5.3. Maximum output per response: GLM-5.3 up to 131,072, GPT-6.1 Sol up to 128,000, Muse Spark 1.2 up to 131,072 tokens.

GLM-5.3 accepts text; GPT-6.1 Sol accepts text, images and PDFs; Muse Spark 1.2 accepts text, images, PDFs, audio and video. Muse Spark 1.2 handles the widest range of inputs.

GLM-5.3 publishes its weights and can be self-hosted; GPT-6.1 Sol and Muse Spark 1.2 is proprietary.

GPT-6.1 Sol is the newest, released Sep 29, 2026. GLM-5.3 came out Aug 14, 2026; Muse Spark 1.2 came out Aug 5, 2026. Knowledge cutoff: GPT-6.1 Sol Apr 30, 2026.

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.