Veo 3.1 Fast

AI Video Generation Model

Video #3 $$$$ · 10¢

Google's fast video generation model producing 720p/1080p video up to 8 seconds with optional native audio including synchronized sound effects, ambient noise, and dialogue with lip-sync

8 seconds
Max Video Duration
Supported Modes
Text to Video Image to Video
Active

Details

Model ID
veo-3.1-fast
Also known as: veo-3-1-fast, veo-3.1-fast-generate-001
Creator
Family
veo
Released
October 2025
Tags
video-generation text-to-video image-to-video audio-generation
// Get Started

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Available at 1 provider

Starting from

$0.100 /second via Gemini API

Prices shown are in USD

Full pricing details

Providers & Pricing (1)

Veo 3.1 Fast is available exclusively through Gemini API, starting at $0.1/video.

Gemini API
Text to Video Image to Video
gemini/veo-3.1-fast
Provider Model ID: veo-3.1-fast-generate-preview

Output

Second Audio
$0.200
Second No audio
$0.100
View official pricing • As of

veo-3-1-fast API Async video generation

Base URL
https://api.lumenfall.ai/v1
Model
veo-3.1-fast

Code Examples

Image to Video

/v1/videos/generations
# Step 1: Submit image-to-video request
VIDEO_ID=$(curl -s -X POST \
  https://api.lumenfall.ai/v1/videos \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "veo-3.1-fast",
    "prompt": "",
    "image_url": "https://example.com/start-frame.jpg",
    "duration": "10",
    "aspect_ratio": "16:9"
  }' | jq -r '.id')
echo "Video ID: $VIDEO_ID"
# Step 2: Poll for completion
while true; do
  RESULT=$(curl -s \
    https://api.lumenfall.ai/v1/videos/$VIDEO_ID \
    -H "Authorization: Bearer $LUMENFALL_API_KEY")
  STATUS=$(echo $RESULT | jq -r '.status')
  echo "Status: $STATUS"
  if [ "$STATUS" = "completed" ]; then
    echo $RESULT | jq -r '.output.url'
    break
  elif [ "$STATUS" = "failed" ]; then
    echo $RESULT | jq -r '.error.message'
    break
  fi
  sleep 5
done

Parameter Reference

Required Supported Not available

Core Parameters

Parameter Type Description Modes
prompt string Required. Text prompt for video generation
T2V I2V
negative_prompt string Negative prompt to guide generation away from undesired content
T2V I2V
duration number Video duration in seconds
T2V I2V

Size & Layout

Parameter Type Description Modes
size string Video dimensions as WxH pixels (e.g. "1920x1080") or aspect ratio (e.g. "16:9")
1365x768 768x1365
WxH determines both shape and scale (aspect_ratio and resolution are ignored when size is provided). W:H format is equivalent to aspect_ratio.
T2V I2V
aspect_ratio string Aspect ratio of the output video (e.g. "16:9", "1:1")
9:16 16:9
Controls shape independently of scale. Use with resolution to control both. If size is also provided, size takes precedence. Any ratio is accepted and mapped to the nearest supported value.
T2V I2V
resolution string Output resolution tier (e.g. "1K", "4K")
1K
Controls scale independently of shape. Higher tiers produce larger videos and cost more. If size is also provided, size takes precedence for scale. Any tier is accepted and mapped to the nearest supported value.
T2V I2V
1K 2 sizes
Output size aspect_ratio + resolution
768 × 1365 "768x1365" or "9:16" + "1K"
1365 × 768 "1365x768" or "16:9" + "1K"

How these parameters work

size

Exact pixel dimensions

"1920x1080"
aspect_ratio

Shape only, default scale

"16:9"
resolution

Scale tier, preserves shape

"1K"

Priority when combined

size aspect_ratio + resolution aspect_ratio resolution

size is most specific and always wins. aspect_ratio and resolution control shape and scale independently.

How matching works

Shape matching – we pick the closest supported ratio. Ask for 7:1 on a model with 4:1 and 8:1, you get 8:1.
Scale matching – providers use different tier formats: K tiers (0.5K 1K 2K 4K) or megapixel tiers (0.25 1). If the exact tier isn't available, you get the nearest one.
Dimension clamping – if a model has pixel limits, we clamp dimensions to fit and keep the aspect ratio intact.

Media Inputs

Parameter Type Description Modes
input_reference array Required. Input image(s) to animate into video
T2V I2V

Audio

Parameter Type Description Modes
generate_audio boolean Whether to generate audio alongside video
T2V I2V

Output & Format

Parameter Type Description Modes
n integer Number of videos to generate
Default: 1
Gateway generates multiple videos in parallel even if provider only supports 1.
T2V I2V

Parameter Normalization

How we handle parameters across different providers

Not every provider speaks the same language. When you send a parameter, we handle it in one of four ways depending on what the model supports:

Behavior What happens Example
passthrough Sent as-is to the provider style, quality
renamed Same value, mapped to the field name the provider expects prompt
converted Transformed to the provider's native format size
emulated Works even if the provider has no concept of it n, response_format

Parameters we don't recognize pass straight through to the upstream API, so provider-specific options still work.

Veo 3.1 Fast FAQ

How much does Veo 3.1 Fast cost?

Veo 3.1 Fast starts at $0.1 per video through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.

How do I use Veo 3.1 Fast via API?

You can use Veo 3.1 Fast through Lumenfall's OpenAI-compatible API. Send requests to the unified endpoint with model ID "veo-3.1-fast". Code examples are available in Python, JavaScript, and cURL.

Which providers offer Veo 3.1 Fast?

Veo 3.1 Fast is available through Gemini API on Lumenfall. Lumenfall automatically routes requests to the best available provider.

Try Veo 3.1 Fast in Playground

Generate images with custom prompts — no API key needed.

Open Playground