Muse Spark 1.2 vs GPT-5.6 Sol vs GLM-5.3

Muse Spark 1.2 is the better all-round choice, scoring 71/100 against GPT-5.6 Sol (66) and GLM-5.3 (63). It leads on inputs & features. GPT-5.6 Sol wins on capability. 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-5.6 Sol costs $4.00 input / $20.00 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 $8.00 for GPT-5.6 Sol (4× as much).

GPT-5.6 Sol scores higher on the Capabilities Index (ECI): GPT-5.6 Sol 162.6 (#12 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 (159.6–166.2 vs 154.3–158.5), so the gap is a real one. On individual benchmarks: SimpleQA Verified — GPT-5.6 Sol 69.7%, Muse Spark 1.2 60.3%, GLM-5.3 41.0%.

There are no published SWE-bench Verified results for Muse Spark 1.2, GPT-5.6 Sol and GLM-5.3 yet, so there is no like-for-like coding score. On overall capability, GPT-5.6 Sol leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

GPT-5.6 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: Muse Spark 1.2 up to 131,072, GPT-5.6 Sol up to 128,000, GLM-5.3 up to 131,072 tokens.

Muse Spark 1.2 accepts text, images, PDFs, audio and video; GPT-5.6 Sol accepts text, images and PDFs; GLM-5.3 accepts text. Muse Spark 1.2 handles the widest range of inputs.

GLM-5.3 publishes its weights and can be self-hosted; Muse Spark 1.2 and GPT-5.6 Sol is proprietary.

GLM-5.3 is the newest, released Aug 14, 2026. Muse Spark 1.2 came out Aug 5, 2026; GPT-5.6 Sol came out Jul 9, 2026. Knowledge cutoff: GPT-5.6 Sol Feb 16, 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.