Suno's versions aren't separate models on Apiframe, they're a single parameter. Every request goes to the same model ID, suno, and sunoParams.model_version picks which underlying Suno version generates the track. That's a real, useful difference from Kling, Hailuo, or GPT Image on this platform, where each version is its own model ID and switching means calling a different endpoint entirely. Here, switching versions is a one-line change.
The lineup
| model_version value | Prompt limit (custom mode) | Style limit (custom mode) | Notes |
|---|---|---|---|
| V4 | 3,000 characters | 200 characters | Earliest version Apiframe exposes |
| V4_5 | 5,000 characters | 1,000 characters | Faster generation, longer max tracks |
| V4_5ALL | 5,000 characters | 1,000 characters | Smarter and faster prompting |
| V4_5PLUS | 5,000 characters | 1,000 characters | Apiframe's default when the field is omitted |
| V5 | 5,000 characters | 1,000 characters | Faster generation, improved musicality |
| V5_5 | 5,000 characters | 1,000 characters | Most customizable output of the set |
Non-custom mode (custom_mode: false) caps the prompt at 500 characters regardless of which version you pick, the longer limits above only apply once you switch to custom/lyrics mode.
What actually changes between versions
Apiframe's own docs list the accepted model_version values and their character limits, but don't describe what each version sounds or behaves like beyond that. Kie.ai, an independent third party that also offers these same underlying Suno versions through its own API, publishes descriptive framing for each one worth citing directly rather than guessing:
V4 is described as focused on improved vocal quality, capped at shorter tracks (max 4 minutes).
V4_5 extends max track length to 8 minutes and adds what Kie.ai describes as smart prompting and faster generation.
V4_5PLUS, Apiframe's default, adds richer sound and new creative controls on top of V4_5.
V4_5ALL is framed as a smarter, faster variant within the same generation.
V5 is described as prioritizing faster generation with improved musicality over V4_5.
V5_5 is framed around more customizable, personalized output, Kie.ai's own description calls it "unleash your voice."
Treat this as directional rather than a precise spec, since it comes from a separate provider's marketing language rather than Suno's own documentation, but it's the closest available description of what changes beyond raw character limits.
Pricing: flat across every version
All six values cost the same 11 credits per generation on Apiframe, whether you pick the oldest (V4) or newest (V5_5). There's no premium tier for newer versions, so defaulting to the newest one costs nothing extra.
Which version to use
For new projects, V5 or V5_5 are the current top of the lineup and cost the same as every older version, so there's little reason to default to an older one unless you have a specific reason. Reasons that might still point you toward an older version: matching the sound of tracks you generated previously with that version for consistency in a series, or working with a workflow that doesn't need the longer prompt or style limits the newer versions allow.
Switching versions in code
Since every version runs through the same model ID, switching is a single field:
import requests
def generate(prompt, model_version, style):
return requests.post(
"https://api.apiframe.ai/v2/music/generate",
headers={"X-API-Key": "afk_your_api_key_here"},
json={
"prompt": prompt,
"model": "suno",
"sunoParams": {"model_version": model_version, "style": style},
},
)
# Default recommendation for new projects
track = generate("a warm acoustic folk song about long drives", "V5_5", "folk, acoustic")
# Matching an older track's version for series consistency
matched = generate("a warm acoustic folk song, part two", "V4_5PLUS", "folk, acoustic")No separate account, no re-integration, just a different value in one field.
Get an API key and start with free credits, or try any version directly in Apiframe Studio without writing code. Full parameter reference is in the docs, and current plan pricing is on the pricing page. For a full walkthrough of the Suno API on Apiframe, see the Suno API Guide. If you're weighing Apiframe against other ways to call Suno, see Best Suno API Providers Compared.
FAQ
Is V5.5 a separate model from V5 on Apiframe?
No. Both are values of the same model_version parameter on the single suno model ID, not separate models or endpoints.
Does picking a newer version cost more?
No. All six accepted values cost the same flat 11 credits per generation.
What happens if I don't set model_version?
Apiframe defaults to V4_5PLUS.
Can I mix versions across a project?
Yes, since it's just a parameter value, different requests in the same project can use different versions freely.
Does the version affect how long a track can be?
Indirectly, through prompt and style character limits in custom mode. V4 caps custom-mode prompts at 3,000 characters and style at 200; every later version allows 5,000 and 1,000 respectively. Non-custom mode is capped at 500 characters regardless of version.
Which version should I use for a brand new project?
V5 or V5_5, the newest available, at no extra cost over older versions.