STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Beam 1.0 501B A23B vs Kolibri-1

Beam 1.0 501B A23B leads Kolibri-1 by 18.3 points on StealthMark, 31.9 to 13.6. It leads on 6 of the 7 benchmarks with results for both and Kolibri-1 on 1. Beam 1.0 501B A23B scores higher on Newton's Mirror, with its largest category advantage in state at 600 ms.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

31.9/100Overall rank 42/53
13.6/100Overall rank 52/53

General Intelligence

30.9/100
12.3/100

Visual Intelligence

33.8/100
15.0/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

  • Kolibri-1Multi-step reasoning not measured

Open or local

Open modelApache 2.0
Local modelOpen model · Apache-2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Beam 1.0 501B A23B
  • Kolibri-1
  • Other models
  • Median

DATASHEET

Specs and pricing

Beam 1.0 501B A23B scores higher on StealthMark and runs 5.9× faster in our speed test. Both take about 1M tokens of context.

  • Beam 1.0 501B A23B
  • Kolibri-1
  • Other models
  • Median
PricePer 1M output tokens, input below
Beam 1.0 501B A23B: $1$0.25 inputKolibri-1: No list price
Context windowTokens per request, max output below
Beam 1.0 501B A23B: 1MTied128K max outputKolibri-1: 1MTied
Output speedTokens per second, our measurement
Beam 1.0 501B A23B: 9725.9× fastertokens/sKolibri-1: 166tokens/s
SizeTotal and active parameters
Beam 1.0 501B A23B: 501B23.4B activeKolibri-1: 78.1B3.46B active
Developer
Reflection AIAleph Alpha
Released
16 Oct 20263 Oct 2026
Origin
United StatesGermany
Input → output
Text → textBoth
Architecture
Sparse mixture-of-experts transformer; 52 layers (3 dense, 49 MoE), 256 experts with 8 selected per token; gated GQA and sliding-window attentionMixture-of-Experts with 4:1 sliding-window-attention to global-attention pattern

Full datasheets, every price and sourceBeam 1.0 501B A23B ↗Kolibri-1 ↗

Anticipating threats and planning ahead. Collect coins while avoiding ghosts. Ghosts move before the player each turn, and collisions cost a life. 3 levels in sequence, up to 66 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Beam 1.0 501B A23B 49.4/100Rank 18/47

Survived 1 of 3
Foresight: complete playing field
Level 39 ptsTurn 20 / 20

Points per level

LevelBeam 1.0 501B A23BKolibri-1
Level 1Second Thoughts
18 ptsOut of lives
No run
Level 2Pressure Pot
9 ptsOut of lives
No run
Level 3Hide or Flight
9 ptsSurvived
No run

Cooperative planning and learning from experience. Coordinate two robots to push numbered cores onto matching sockets. Pressure plates hold doors open; moving either robot uses one turn. 5 levels in sequence, up to 152 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Beam 1.0 501B A23B 37.3/100Rank 29/48

Cleared 2 of 5
Latch: complete playing field
Level 55 ptsTurn 30 / 40

Points per level

LevelBeam 1.0 501B A23BKolibri-1
Level 1Hold the door
5.2 ptsCleared
No run
Level 2Crossfeed
9.6 ptsCleared
No run
Level 3Relay vault
11.2 ptsFinished early
No run
Level 4Passing bay
3.6 ptsFinished early
No run
Level 5Second thoughts
5 ptsFinished early
No run

Newton's Mirror

Same task instructions

Physics, perspective and recursive reflections, tested together. Explore the test ↗

The judgment

Beam 1.0 501B A23B

Central object placement is fairly close, but the defining mirrored-room structure is missing. The paint colors suggest the required contact order without establishing their different interaction histories. The faint floor oval does not demonstrate valid reflection geometry, so it earns no reflection credit. Rounded volume and glossy paint provide limited material credit despite weak metallic finishes and oversized paint bodies.

Kolibri-1

A segmented gray perimeter surrounds a black field containing one large, low-positioned gray sphere and two small colored circles. Rounded volume and restrained paint scale earn partial material credit. The image does not demonstrate the required optical structure, while paint history, airborne black and settled support remain largely unresolved.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
State at 600 ms20.5/259.5/25
Camera and placement11.5/151.5/15
Reflections2.0/1200.0/120
Materials and scale3.0/103.0/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

Beam 1.0 501B A23B

An appealing expression and warm palette support a coherent simple cartoon. The central polishing joke is not legible: the cloth is unresolved and the nose sits away from the fan. Pointed radial plates, uncertain limb attachments and weak ground contact limit construction, while restrained surface detail limits material richness.

Kolibri-1

A restrained ivory, teal and green palette gives the image simple graphic coherence. Execution remains rudimentary: detached oval wings, ambiguous central anatomy and unclear feeding contact prevent a convincing hummingbird scene. The requested feather structure, botanical detail, lighting and enclosing arch are largely unresolved.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
Task & likeness4.0/102.5/10
Anatomy & construction3.5/102.0/10
Space & placement5.5/103.0/10
Light & reflections5.5/102.0/10
Purposeful detail4.5/101.5/10
Artistry & character4.0/101.5/10
Materials & effects4.5/102.0/10
Visual integrity7.0/105.5/10

Benchmark task

Beam 1.0 501B A23B

A golden pangolin polishes its oversized amber tail while its nose smudges the same scale. The scene tests expressive anatomy, physical contact and contrasting translucent, polished and soft materials.

Kolibri-1

A jewel-coloured hummingbird hovering in flight tests avian anatomy, delicate structure and iridescent surface detail.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Beam 1.0 501B A23B

The candidate shows a faint warm oval against an almost entirely black field. Minimal placement and smooth tonal variation are visible, but the portrait, anatomy, crossed hands and landscape remain unreadable. The saved comparisons provide no specific evidence supporting a change to the baseline categories.

Kolibri-1

The candidate offers a clean, highly simplified frontal portrait with warm skin and dark hair. Its oversized oval face, schematic features and unresolved body provide little Mona Lisa likeness. Missing crossed hands, clothing detail and landscape remove essential parts of the original composition; smooth gradients supply only limited volume.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
Task & likeness0.0/100.5/10
Anatomy & construction0.0/100.5/10
Space & placement0.0/100.0/10
Light & reflections0.5/100.0/10
Purposeful detail0.0/100.0/10
Artistry & character0.0/100.5/10
Materials & effects0.0/100.5/10
Visual integrity0.0/100.5/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Different task instructions

Creativity, perspective and visual beauty.

The judgment

Beam 1.0 501B A23B

A coherent, cheerful beach illustration fulfills the main subjects with clean shapes and a strong sunset focal point. Its basic geometric construction, ambiguous animal anatomy, shallow depth and schematic lighting limit its accomplishment. Decorative details provide interest without developing intricate forms or convincing physical surfaces.

Kolibri-1

A recognizable sunset beach has an appealing purple-orange gradient and clean geometric edges. Birds and animals remain unresolved, terrain obscures the relationship between shore and water, and reflections are absent. Sparse detail, flat materials and limited activity keep the drawing elementary despite its tidy rendering.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
Task & likeness7.0/102.5/10
Anatomy & construction5.0/100.5/10
Space & placement6.0/103.0/10
Light & reflections5.0/101.0/10
Purposeful detail5.5/100.5/10
Artistry & character4.0/101.0/10
Materials & effects5.0/100.5/10
Visual integrity5.0/103.0/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Different task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Beam 1.0 501B A23B

This benchmark has not been assessed yet.

Kolibri-1

This benchmark has not been assessed yet.

Benchmark task

A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.

Raccoon

Different task instructions

Scene composition and interacting subjects.

The judgment

Beam 1.0 501B A23B

A cheerful, readable illustration with recognizable animals, expressive faces and useful accessories. Simple rounded construction limits complexity, while ambiguous steering attachments and weak hull-to-water contact reduce physical coherence. Lighting and surface effects establish the setting without convincing environmental interaction.

Kolibri-1

Clean shapes and a readable coral platform provide basic graphic clarity, but the animal construction remains fragmented. A recognizable raccoon riding the dog's back, connected steering and convincing water contact are not demonstrated. Sparse detail, flat subjects and absent movement effects support retaining the baseline category assessments.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
Task & likeness5.0/101.5/10
Anatomy & construction3.5/101.0/10
Space & placement5.5/101.0/10
Light & reflections4.0/100.0/10
Purposeful detail6.5/100.5/10
Artistry & character3.5/100.5/10
Materials & effects5.0/100.5/10
Visual integrity6.5/103.5/10

Benchmark task

A jet-ski scene pairs a canine driver with a raccoon passenger. It tests the placement and contact of interacting subjects, along with vehicle construction.

Pelican

Different task instructions

Subject construction and spatial relationships.

The judgment

Beam 1.0 501B A23B

A cheerful, clearly readable pelican-and-bicycle illustration with clean contours and balanced composition. Simple geometric construction limits artistic complexity, while ambiguous neck and steering overlaps, merged pedal contacts and an incomplete drivetrain weaken physical coherence.

Kolibri-1

Clean shapes and aligned wheels establish a readable schematic scene. Pelican likeness, riding support and bicycle mechanics remain substantially unresolved. Sparse detail and flat surfaces limit expression and volume. Strong edge and fill integrity is a separate success and does not repair the construction.

Score breakdown

CategoryBeam 1.0 501B A23BKolibri-1
Task & likeness5.5/101.5/10
Anatomy & construction4.5/101.5/10
Space & placement5.0/101.5/10
Light & reflections4.0/103.0/10
Purposeful detail4.0/101.5/10
Artistry & character4.0/101.0/10
Materials & effects4.0/101.0/10
Visual integrity5.5/103.5/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.