Grok Imagine costs 5 credits per image and tops out at 1K with five aspect ratios; Grok Imagine Pro costs 10 credits and gives you nine aspect ratios plus a 2K tier that is billed at the same flat rate as its 1K tier. Both are xAI image models, both do text-to-image and image-to-image on VdoBloom, and both charge one flat price with no resolution ladder. The decision is simple: if the image is a draft, take the base model and run two of them for the price of one Pro. If the image is final, take Pro and set it to 2K, because 2K costs you nothing extra.

What each model actually is

Grok Imagine is the standard xAI image model, routed through Kie. It runs as two endpoints under one picker entry: a text-to-image path and an image-to-image path that accepts exactly one reference photo. Prompts are capped at 5,000 characters, and on the editing path the prompt is optional — you can hand it a photo with no instruction and let it reinterpret.

Grok Imagine Pro is the Image Pro checkpoint, routed through Runware. It also does both directions, but it adds a resolution control, four extra aspect ratios including the tall 1:2 and wide 2:1 frames, and it always requires a prompt, even in editing mode. In editing mode the output resolution auto-matches the aspect ratio of the image you upload, so you do not choose a frame — the reference decides it.

Spec versus spec versus price

Spec	Grok Imagine	Grok Imagine Pro
Credits per image	5	10
Dollar cost at Lite rate	$0.25	$0.50
Resolutions	Single tier (1K class)	1K or 2K, same price
Aspect ratios	1:1, 2:3, 3:2, 16:9, 9:16	1:1, 3:4, 4:3, 9:16, 16:9, 2:3, 3:2, 1:2, 2:1
Text-to-image	Yes	Yes
Image-to-image	Yes, 1 reference image	Yes, 1 reference image
Prompt limit	5,000 characters	No hard cap in the editor
Prompt required when editing	No	Yes
Provider route	Kie	Runware
Images per $15 Lite month	60	30

Dollar figures use the Lite plan rate of $15 for 300 credits, which makes one credit $0.05. Neither model has resolution-tiered pricing in the credit system, so nothing in the settings panel can change what a render costs. That is different from most of the catalogue — GPT Image 2, for example, charges 3, 5 and 8 credits for 1K, 2K and 4K. Full plan details are on the pricing page.

The 2K tier is the whole argument for Pro

Here are the real output dimensions Pro renders at. The base model has no equivalent control.

Aspect ratio	Pro at 1K	Pro at 2K	Both cost
1:1	1024 x 1024	2048 x 2048	10 credits
9:16	768 x 1408	1536 x 2816	10 credits
16:9	1408 x 768	2816 x 1536	10 credits
2:3	864 x 1296	1728 x 2592	10 credits
3:2	1296 x 864	2592 x 1728	10 credits
1:2	704 x 1408	1408 x 2816	10 credits
2:1	1408 x 704	2816 x 1408	10 credits

If you have already decided to spend 10 credits, leaving Pro on its 1K default is simply throwing away four times the pixel count for free. The only reason to keep 1K is speed, since the larger render takes longer to come back.

Where the base model wins

Iteration. At 5 credits a render, a new account’s 10 free starter credits buy two Grok Imagine attempts but only one Pro attempt. When you do not yet know what you want — the composition is unsettled, the prompt is still being tuned, you are trying five variations of a pose — the cheaper model is the correct one, and you promote the winning prompt to Pro at the end. Ten base drafts plus one Pro final is 60 credits; ten Pro drafts is 100 credits for the same finished image.

The base model also has the friendlier editing path. Because its prompt is optional on image-to-image, you can upload a photo and let it re-render with no instruction at all, which is a genuinely useful way to get a stylistic reinterpretation you would not have thought to ask for. Pro refuses an empty prompt.

Where Pro wins outright

Frames the base model cannot make. The 1:2 and 2:1 ratios are Pro-only, and those are exactly the shapes you need for a tall app-store screenshot column or a wide website hero banner. So are 3:4 and 4:3, the classic print and feed ratios. The base model’s five ratios cover social square, portrait and landscape video, and little else.

Pro is also the one to use when the render is the deliverable rather than a step — a print asset, a thumbnail that will be scaled, a product shot going onto a storefront. And Pro is supported by the pose variations tab, which fans one prompt out into a batch of poses and scenarios with the subject held constant.

A worked example

You want a 9:16 poster of a neon-lit street food stall for a Reels cover. Start on the image generation tab with Grok Imagine at 9:16 and write three prompt variants: one wide-establishing, one close on the wok, one with a person mid-serve. Three renders, 15 credits, 75 cents. Pick the composition that worked, switch the model to Grok Imagine Pro, paste the winning prompt, set resolution to 2K and render once. Total spend 25 credits, and you end with a 1536 x 2816 file instead of a 768 x 1408 one.

For editing work the same logic applies on the image editing tab: draft the edit instruction against the base model until the phrasing lands, then run the final pass on Pro at 2K. If the photo you upload contains a real person, you must have that person’s consent before using it.

When neither is right

Both Grok models take exactly one reference image. If your edit depends on combining several inputs — a product plus a background plus a style board — you need a model built for multi-reference work: GPT Image 2 takes 10 images at 3 to 8 credits depending on resolution, and Seedream 5 Lite takes up to 14 at 6 credits. If you need 4K, neither Grok model reaches it and GPT Image 2 at 8 credits does. And if you want the cheapest possible draft, Z-image Turbo at 2 credits undercuts Grok Imagine by more than half.

The verdict

Grok Imagine is the drafting model and Grok Imagine Pro is the finishing model, and the price gap is exactly 2 to 1, which makes the workflow obvious: explore cheap, finish expensive, and never run Pro at 1K unless you are in a hurry. Choose Pro from the start only when your output shape is 1:2, 2:1, 3:4 or 4:3, because the base model cannot produce those at all.

Frequently asked questions

Does Grok Imagine Pro at 2K cost more than at 1K?

No. Pro is a flat 10 credits at either resolution — there is no resolution-tiered variant for it in the credit system. Set it to 2K unless you need the faster turnaround.

How many reference images can each model take?

One. Both the base model and Pro send a single reference image to the provider, regardless of how many you stage in the editor.

Can Grok Imagine do 4K?

No. The base model has a single output tier and Pro stops at 2K, which is 2048 x 2048 on a square. For 4K stills, use GPT Image 2 at 8 credits.

Is a prompt required to edit a photo?

Only on Pro. Grok Imagine’s image-to-image path accepts an image with no prompt at all and reinterprets it; Pro rejects an empty prompt.

Do I get a watermark-free download?

On any paid plan, yes, along with commercial rights. New accounts get 10 free credits with no card, enough for two Grok Imagine renders or one Pro render, but those downloads carry a watermark.

Grok Imagine vs Grok Imagine Pro: 5 Credits or 10?