Seed 2.1 Pro (ByteDance) posted the highest overall score in our July 2026 video-understanding bench: 89.0/100 on basic understanding and 89.4/100 on the transition-analysis special, across ten film clips and five other video categories. But the most useful finding isn’t the ranking — it’s that the six models tested don’t watch video the same way at all. Kimi 2.7 Code (Moonshot AI) fuses frames into motion-aware blocks before its language model ever sees them; Seed reads timestamped frames and reassembles time in context; GPT-5.5 (OpenAI) and Claude Opus 4.8 (Anthropic) worked agent-style from extracted frames plus transcripts; and Gemini 3.1 Pro (Google) — the only native audio-plus-video model in the set — finished last this round at 75.5/100. Pick by task, not by leaderboard.
Scores at a glance
| Model | Maker | Basic understanding | Transition special | Read it as |
|---|---|---|---|---|
| Seed 2.1 Pro | ByteDance | 89.0 | 89.4 | Strongest recognition, timelines, visual detail |
| Kimi 2.7 Code | Moonshot AI | 86.9 | 83.7 | Best motion intuition on short clips |
| GPT-5.5 | OpenAI | 86.8 | 84.3 | Clearest written analysis |
| Claude Opus 4.8 | Anthropic | 85.1 | 84.2 | Most disciplined evidence chain |
| Seed 2.0 Lite | ByteDance | 84.0 | 89.5 | Lightweight control; best transition score in the set |
| Gemini 3.1 Pro | 75.5 | 65.3 | Native audio+video, weakest scores this round |
All scores on one normalized 100-point scale. How to read them: these are rubric-scored indexes, useful for deciding which transcripts to read first — they are not ground-truth-validated measurements. The limitations section below is part of the result.
Which model for which video task
| If you need… | Use this |
|---|---|
| Short-clip action, rhythm, and transition analysis | Kimi 2.7 Code |
| Replicating or critiquing an animation / motion demo | Kimi 2.7 Code |
| Long-video summarization, streaming, sparse footage | Seed 2.1 Pro |
| Screen recordings, UI detail, small on-screen text | Seed 2.1 Pro (or 2.0 Lite for cost) |
| Cut and transition detection on a budget | Seed 2.0 Lite |
| Report-ready written analysis of theme and editing intent | GPT-5.5 |
| Cautious analysis with explicit uncertainty boundaries | Claude Opus 4.8 |
| One native audio+video API, tolerating this round’s scores | Gemini 3.1 Pro, with tight output constraints |
One warning that falls out of the architecture section below: if your only path to a model is an agent harness that samples video into screenshots — the default for coding agents like Claude Code or Codex today — you are running at reduced capability. Static frames survive that path; pacing, motion quality, and cut timing do not.
Three ways a model can “watch” a video
The scores make more sense once you know what each model actually receives. Three distinct pipelines showed up in this bench, and each one decides in advance what the model can and cannot see.
Frame extraction (GPT-5.5 and Claude Opus 4.8, agent-style). The video is sampled into a stack of independent stills, usually with a separate audio transcript. Per-frame detail survives well; everything that happens between frames — a car accelerating, a camera pushing in, an edit rhythm suddenly doubling — has to be imagined by the language model. Good for static checks; structurally blind to motion.
Fused clip encoding (Kimi 2.7 Code). Short runs of consecutive frames are packed into spatio-temporal blocks before the language model sees them, so the vision encoder itself understands “a hand is rising, the light is dimming, the camera is pulling back.” Motion arrives pre-understood, which is why Kimi’s short-clip action and transition readings feel like a director’s notes. The cost: per-frame detail gets diluted in the packing.
Timestamped sampling (Seed 2.1 Pro and Seed 2.0 Lite). Every sampled frame keeps single-image fidelity and carries its timestamp, with sampling density adapting to the task. The language model reassembles motion by reasoning over the timeline. This scales to long videos, meeting recordings, and screen captures with small UI text — while dense, fast action still has to be stitched together by the model.
Native audio+video (Gemini 3.1 Pro) is the fourth path: sound and picture enter the model together, no transcript step. In principle that’s the strongest position; in this round, low-FPS visual sampling blind spots and loosely controlled output granularity kept its scores at the bottom of the table. Architecture opens a ceiling — it doesn’t guarantee the floor.
| Frame extraction | Fused clip encoding | Timestamped sampling | |
|---|---|---|---|
| The model receives | A stack of independent stills | Frame runs pre-packed into spatio-temporal blocks | Stills, each stamped with its timestamp |
| Motion is understood by | The LLM, imagining between frames | The vision encoder, before the LLM | The LLM, reasoning over timestamps |
| Strongest at | Static-frame checks, written reasoning | Short-clip action, rhythm, transitions | Long video, streaming, small UI text |
| Main cost | Frame-to-frame relations are lost | Per-frame detail diluted | Dense action still reassembled downstream |
One 30-second clip, six readings
The film set’s first clip is the climactic mansion shootout from Scarface — about 30 seconds of build-up, a grenade blast, then spray-fire montage. It’s a good separator because it mixes hard cuts, in-scene smoke occlusion, and real transitions, and models that can’t tell those apart give themselves away. Every model answered the same “basic conclusion” field. Excerpts (the bench ran in Chinese; quotes below are translated, except Gemini’s, which replied in English on its own):
Kimi 2.7 Code: “The edit builds in three beats — line, pause, eruption: a tracking long take establishes pressure, cross-cut shot/reverse-shots form the standoff, a signature line triggers the grenade blast, and the sequence collapses into rapid, fragmented spray-fire montage. In about 30 seconds the audiovisual language compresses Tony’s mania, isolation, and violent aesthetics.”
Claude Opus 4.8: “Violent climax of a classic crime film (visually consistent with the mansion-shootout ending of Scarface; Chinese subtitles present). The 30s structure is a textbook build-and-release: the first ~22s use long takes and slow cuts to establish dread; at 22.7s it switches to high-frequency hard cuts, syncing muzzle flashes with the edit. The editing logic serves the emotion curve, not information.”
GPT-5.5: “Interior gunfight/standoff; a suited man in a luxury office returns fire after being ambushed. The edit maintains spatial continuity through the room’s main axis, the doorway attack, and smoke occlusion.”
Gemini 3.1 Pro: “Iconic action sequence utilizing rapid hard cuts, extreme sound design, and dynamic camera angles to convey chaotic violence and character mania.”
Three things worth noticing, because they generalize across the whole bench. First, the specificity gradient: Kimi and Claude give time-anchored, falsifiable structure (“at 22.7s”, “three beats”); Gemini’s line is accurate but contains nothing you could check. Second, hedging discipline: Claude was the only model that declined to positively identify the film, marking it “visually consistent with” Scarface instead of asserting it — mid-pack on score, best in the set at knowing what it didn’t know. Third, verbosity is not quality: across the multi-type sets Gemini wrote some of the longest field responses while scoring lowest. Length is not evidence; timestamps are.
Model by model
Seed 2.1 Pro — 89.0 basic / 89.4 transitions
The strongest overall this round. Type recognition, timeline reconstruction, and visual-detail coverage led the set, and the timestamped pipeline shows in how often its claims arrive with usable time references. Double-check before relying on it: strong recognition did not always mean reliable audio-visual claims, long outputs occasionally truncated, and fine cut-point assertions still need evidence review.
Kimi 2.7 Code — 86.9 basic / 83.7 transitions
The best motion intuition in the set. Fused clip encoding is visible in the transcripts: action beats, force, and cut rhythm on short clips read the way an editor would describe them, and its judgments about what a clip is for were consistently usable. Watch for: implicit cuts hidden inside high-motion sequences, small on-screen text, and external-knowledge claims that need verification.
GPT-5.5 — 86.8 basic / 84.3 transitions
Explanation-first. The strongest at organizing theme, editing intent, and audio-visual relations into prose you could paste into a report. Frame-level cut timing needs tool assistance, it goes conservative when the audio track is quiet, and its plausible extrapolations are good enough that you have to make sure they stay labeled as extrapolations.
Claude Opus 4.8 — 85.1 basic / 84.2 transitions
Ran agent-style — extracted frames plus audio transcription — and turned that constraint into the cleanest evidence discipline in the bench: tool-cited claims, explicit uncertainty fields, hedged identifications. No native hearing, so speech analysis depends on the transcript, and motion detail is bounded by frame sampling.
Seed 2.0 Lite — 84.0 basic / 89.5 transitions
The surprise of the round: a lightweight tier that posted the best transition-special score in the set and multi-type field completeness close to its bigger sibling. As a cost/quality control group it earned a permanent slot. Film-set basic understanding trails 2.1 Pro, and complex audio-visual explanations need review.
Gemini 3.1 Pro — 75.5 basic / 65.3 transitions
The only native audio+video model in the set finished last after score normalization onto the shared 100-point scale. The bench notes point at low-FPS visual sampling blind spots and output granularity that needed heavy prompt constraint — depth was not the problem; its responses were among the longest. Treat this as a this-round result for this rubric, not a verdict on native-AV architecture.
What these scores can’t tell you
This section is part of the result, not a disclaimer.
- The scores are a reading index, not a ruling. Field responses were scored against a shared weighted rubric and normalized to 100 points. No human-labeled ground truth sat underneath this round — so “89.0 vs 86.9” is a strong signal about which transcripts read better, not a calibrated capability gap.
- No cut-point ground truth yet. Transition claims were judged on evidence quality and coherence, not against a human-labeled list of true cuts. A model can sound right about an edit it misplaced.
- Pipelines differ by design. Each model ran its native path (frames, fused blocks, timestamps, native AV). That’s deliberate — it’s what you actually get as a user — but it means sampling differences are baked into the numbers.
- The next round closes these gaps: unified 8 fps sampling across models, uniform audio transcription, human-labeled cut points, and one scoring scale — upgrading the bench from “can it analyze” to “can it be verified.” This page will be updated when that lands.
How this bench was run
Run by AgentsBench in July 2026. Six checkpoints as tested: Kimi 2.7-code,
Seed 2.1 Pro, Seed 2.0 Lite, Claude Opus 4.8, Gemini 3.1 Pro,
GPT-5.5.
Material. Ten film clips chosen to separate models — an interior-gunfight climax (Scarface finale), a fast travel montage, a black-and-white rain battle, a graphic product ad, the bone-to-spacecraft match cut, a desert/snow car commercial, a long-take spatial reveal, a setup-to-eruption gunfight, a CG siege battle, and an in-car dialogue reversal — plus five more categories: narrative, explainer, AI-generated video, UI/demo recordings, and talking-head.
Fields. On the film set, nine base fields (summary, timeline, transition rhythm, audio analysis, audio-visual relations, edit-point reasoning, shot language, visual language, open questions) plus seven transition-special fields; roughly ten fields per category elsewhere — UI clips get step breakdowns and interface-state analysis, talking-head clips get subtitle recognition and speech-to-visual correspondence, AI-generated clips get character/scene/style-consistency and artifact-drift checks.
Scoring. Every field response scored against a shared rubric with per-field weights, all models normalized to one 100-point scale. Reference evidence for judging: a 2 fps frame timeline and an audio waveform per clip. Prompts and rubric ran in Chinese; excerpts above are translated (Gemini’s reply was in English as produced). The reading order we used — transcripts first, scores second — is the one we recommend.
Why this bench exists at all: video-understanding models are the perception layer of AI video agents — the thing that lets an agent watch, QA, and iterate on its own output instead of shipping blind. How we grade and label claims across this site is documented in the methodology. Spotted an error in a quote, a score, or a claim? Send the source to the contact address in the footer — corrections get dated and logged.
Frequently asked questions
Which AI model is best at video understanding in 2026?
In AgentsBench's July 2026 bench of six models, Seed 2.1 Pro (ByteDance) scored highest overall — 89.0/100 on basic understanding and 89.4/100 on transition analysis — tested across ten film clips plus narrative, explainer, AI-generated, UI-demo, and talking-head sets. Kimi 2.7 Code led on short-clip motion intuition, and GPT-5.5 produced the clearest written analysis. There is no single best; pick by task.
Can GPT-5.5 and Claude analyze video?
Yes, but as of July 2026 both typically work agent-style: the video is sampled into still frames, plus an audio transcript, rather than ingested natively. In our bench that path scored 86.8/100 (GPT-5.5) and 85.1/100 (Claude Opus 4.8) on basic understanding — strong on static detail and written reasoning, weaker on motion and precise cut timing, which live between the sampled frames.
Why did Gemini score low despite native audio-video input?
Gemini 3.1 Pro was the only model in the set that ingests audio and video natively, yet it finished last this round — 75.5/100 basic, 65.3/100 on transitions. The bench notes point to low-FPS visual sampling blind spots and output granularity that needed heavy prompt constraint. Native input is an architectural advantage, but this round's scores show it is not sufficient by itself.
Which AI model is best for detecting cuts and transitions in video?
The two ByteDance Seed models topped the transition special: Seed 2.0 Lite at 89.5/100 — the best transition score in the set — and Seed 2.1 Pro at 89.4/100. Kimi 2.7 Code is strong at explaining transition rhythm on short clips. For any model, frame-level cut timing should still be verified against ground truth before you rely on it.
What's the best AI model for summarizing long videos or screen recordings?
Seed's timestamped adaptive sampling makes it the strongest fit for long material: every sampled frame carries its timestamp, so the model reassembles the timeline in context, and sampling density adapts to the task. That favors hour-long documentaries, meeting recordings, and screen captures with small UI text — with Seed 2.0 Lite as the lower-cost option.
What is the difference between frame extraction and native video understanding?
Frame extraction hands the model a stack of stills, so motion has to be inferred; anything happening between frames — acceleration, camera pushes, rhythm shifts — is invisible. Fused approaches encode consecutive frames together (Kimi 2.7 Code packs short frame runs into spatio-temporal blocks before the language model), so motion arrives already understood. Extraction preserves per-frame detail best; fusion preserves motion best.
Can coding agents like Claude Code or Codex understand video?
Only at reduced capability. Agent harnesses today typically convert video into sampled screenshots, so what the model actually receives is stills — fine for checking static frames or UI states, unreliable for pacing, motion quality, or transition detection. If motion matters, route the clip to a video-native model instead of relying on the agent's default frame dump.
Which model gives the most trustworthy analysis when it isn't sure?
Claude Opus 4.8 was the most disciplined about uncertainty in our transcripts: it hedged the test film's identity as 'visually consistent with' the movie rather than asserting it, flagged its dependence on transcription for speech, and kept a clear tool-evidence chain. It scored 85.1/100 on basic understanding — mid-pack on score, strongest on stated confidence boundaries.
How were these video understanding scores calculated?
Each model analyzed the same clips across scored fields — nine base fields (summary, timeline, transition rhythm, audio, audio-visual relations, edit points, shot language, visual language, open questions) plus seven transition-special fields on the film set, and roughly ten fields per category on the other sets. Field responses were scored against a shared weighted rubric and normalized to one 100-point scale. Scores are an index for reading the transcripts, not ground-truth-validated measurements.
Do higher video understanding scores mean longer, more detailed answers?
No — verbosity and accuracy diverged in this bench. Gemini 3.1 Pro wrote some of the deepest per-field responses in the multi-type sets yet posted the lowest scores, while top-scoring models often answered more briefly with concrete, time-coded evidence. Length is not evidence; timestamps and falsifiable specifics are.