{"id":"muse-spark-open","slug":"muse-spark-open","name":"Muse Spark Open","orgId":"meta","family":"muse-spark-open","releaseDate":null,"availability":"ga","openWeights":true,"license":"muse-model-license","paramsTotal":null,"paramsSource":null,"contextWindow":1048576,"knowledgeCutoff":null,"modelCardUrl":"https://x.com/AIatMeta/status/2110779754274292212","hfRepo":"meta-models/Muse-Spark-Open-816B-A42B","modalities":["text","image","video","file","audio"],"aliases":["Muse Spark Open","meta/muse-spark-open","Meta: Muse Spark Open","Muse Spark Open (Max)","muse spark open"],"aliasNote":null,"origin":"tracked","tracked":{"trackedSince":"2026-10-15","announced":"2026-10-15","blurb":"Meta's open-weight model built for coding and agentic work, aimed at long-horizon tasks, complex software engineering and multi-step reasoning.","api":"none","openWeights":"yes","params":{"text":"816B total / 42B active","source":"Meta's announcement post"},"facts":[{"label":"Focus","value":"Coding and agents"},{"label":"Context","value":"1M tokens","unsure":true,"note":"post text cut off"}],"claims":["The most capable US open-weight model to date."],"sources":[{"kind":"lab","title":"Meta announcement on X","url":"https://x.com/AIatMeta/status/2110779754274292212","date":"2026-10-15"}],"peer":{"slug":"muse-spark","label":"Muse Spark"},"launchPost":true,"pitch":"an open-weight coding and agent model, and the most capable US open-weight model yet","firstBenchmark":{"date":"2026-10-17","benchmarkId":"lmarena-webdev"}},"contextSource":"openrouter","listedSince":"2026-10-16","organization":{"id":"meta","name":"Meta","slug":"meta","country":null,"url":null,"color":"#7B61FF","mark":"M"},"price":{"modelId":"muse-spark-open","provider":"meta","inputPerM":null,"outputPerM":null,"blendedPerM":2.0000000000000004,"tokensPerS":null,"observedAt":"2026-11-03","sourceId":"openrouter"},"answer":{"word":"#18","scope":"Best current rank: #18 in Finance, as of Nov 3, 2026.","lead":"As of Nov 3, 2026, Muse Spark Open is ranked #18 in Finance (since Nov 3, 2026; sources Finance Agent; methodology v1.0). Ranked #18 in Finance. That board does not award a crown.","confidence":"low"},"status":"BENCHMARKED","verdicts":[{"id":"v_overall_general-llm_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"general-llm","category_name":"General LLM","slice":"overall","state":"RANKED","rank":163,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":91.11405835543768,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #163 in General LLM.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#163 in General LLM"},{"id":"v_pareto_general-llm_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"general-llm","category_name":"General LLM","slice":"pareto","state":"RANKED","rank":154,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":87.73946360153255,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #154 in General LLM on best per dollar.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#154 in General LLM (best per dollar)"},{"id":"v_overall_coding_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding","category_name":"Coding","slice":"overall","state":"RANKED","rank":32,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":86.41975308641975,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #32 in Coding.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#32 in Coding"},{"id":"v_open-weights_coding_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding","category_name":"Coding","slice":"open-weights","state":"RANKED","rank":8,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":68.01346801346799,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #8 in Coding.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#8 in Coding (open weights)"},{"id":"v_pareto_coding_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding","category_name":"Coding","slice":"pareto","state":"RANKED","rank":33,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":86.96296296296295,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #33 in Coding on best per dollar.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#33 in Coding (best per dollar)"},{"id":"v_overall_coding-web-dev_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding-web-dev","category_name":"Coding › Web dev","slice":"overall","state":"RANKED","rank":47,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":35.9375,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":null,"rationale":"Ranked #47 in Coding › Web dev.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#47 in Coding › Web dev"},{"id":"v_open-weights_coding-web-dev_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding-web-dev","category_name":"Coding › Web dev","slice":"open-weights","state":"RANKED","rank":12,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":23.07692307692308,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":null,"rationale":"Ranked #12 in Coding › Web dev.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#12 in Coding › Web dev (open weights)"},{"id":"v_pareto_coding-web-dev_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"coding-web-dev","category_name":"Coding › Web dev","slice":"pareto","state":"RANKED","rank":47,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":35.9375,"confidence":"medium","valid_from":"2026-11-03","valid_to":null,"configuration":null,"rationale":"Ranked #47 in Coding › Web dev on best per dollar.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#47 in Coding › Web dev (best per dollar)"},{"id":"v_overall_finance_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"finance","category_name":"Finance","slice":"overall","state":"RANKED","rank":18,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":null,"confidence":"low","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #18 in Finance. That board does not award a crown.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#18 in Finance"},{"id":"v_open-weights_finance_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"finance","category_name":"Finance","slice":"open-weights","state":"RANKED","rank":8,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":null,"confidence":"low","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #8 in Finance. That board does not award a crown.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#8 in Finance (open weights)"},{"id":"v_overall_legal_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"legal","category_name":"Legal","slice":"overall","state":"RANKED","rank":20,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":null,"confidence":"low","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #20 in Legal. That board does not award a crown.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#20 in Legal"},{"id":"v_open-weights_legal_muse-spark-open_2026-11-03_open_RANKED","model":"muse-spark-open","model_name":"Muse Spark Open","category":"legal","category_name":"Legal","slice":"open-weights","state":"RANKED","rank":6,"present_evidence":[],"missing_evidence":[],"coverage":null,"segments":[],"confirm":[],"margin":null,"confidence":"low","valid_from":"2026-11-03","valid_to":null,"configuration":"xhigh","rationale":"Ranked #6 in Legal. That board does not award a crown.","safeguard_flags":[],"co_sota_with":[],"challengers":[],"methodology":"1.0","label":"#6 in Legal (open weights)"}]}