LTX 2 Fast vs Pro at 4K

LTX 2.3 Text to Video Fast is 20 credits, text-to-video, native audio, 4K, 6–20 seconds. LTX 2 Text to Video Pro is 29 credits, text-to-video, native audio, 4K, 6 / 8 / 10 seconds. Both speak. Both are 4K. Fast is the cheap long door. Pro is nine extra credits on a shorter menu. The cards are the minimum job: both bill per second by resolution, 4 and 5 credits a second at SD/HD, 13 and 20 at 4K. Cheap versus Pro. Pro is not more duration. Fast is.

The Fast slug is ltx-2-3-text-to-video-fast. The Pro slug is ltxv2-text-to-video-pro. Different version tokens on the card. A third row, ltx-2-3-text-to-video-pro, is in the catalog too, priced like LTX 2 Pro, with 6 / 8 / 10 seconds and no page of its own. Do not treat Fast and Pro as the same model with a quality toggle. They are two published rows that share a family shape: T2V, native audio, 4K.

There is also LTX 2 Text to Video Fast at 20 credits, 4K, native audio, 6–20 seconds — an older Fast door with the same sticker and the same length menu as 2.3 Fast. This comparison uses the 2.3 Fast slug. If you land on the older Fast card, the meter is still 20 credits, not 29.

Twenty credits and twenty-nine credits are catalog stickers. Do not call Pro a 45% surcharge as if that were a reason. Nine credits is nine credits. The reason to pay it is the Pro pass on a 6 / 8 / 10s 4K take you will actually ship.

Fast at 20 credits: 4K native audio out to 20 seconds

The 2.3 Fast card: audio true, text-to-video, 6 / 8 / 10 / 12 / 14 / 16 / 18 / 20 seconds, 4K, 20 credits. Description: video from a text prompt at 1080p / 1440p / 2160p, 6–20s, with optional native audio generation. The published audio flag is true. Write whether anyone speaks. A 20-second surprise monologue is a long error if the brief was mute motion. A 20-second line that needs to be said is why you are not on Kling Turbo.

Use Fast when:

You need 12–20 seconds at 4K with a native-audio T2V row. Pro cannot. Veo cannot (8s max). Grok can at 720p from 24 credits. Fast is the 4K length door, at 13 credits a second.
You are drafting a sentence. Twenty credits is how you find out whether the prompt wants to be a clip.
6s, 8s, or 10s would fit Pro, but you do not need the Pro pass yet.

When Fast is the wrong pick:

The insertion order is a 6 / 8 / 10s hero you already know is the Pro file. Skipping Pro to save nine credits on the take you will buy media against is a different economy than drafting.
You have a still that must remain frame one. This page is T2V. Fast will invent the plate.
You needed 4 seconds. Fast’s floor is 6s. Veo 3.1 has 4s at 64 credits.

Grok Imagine Video starts at 24 credits, 720p, up to 30s, native audio. Four credits more than Fast, 720p instead of 4K, 30s instead of 20s. If 4K is the floor, Fast is the row, at 13 credits a second. If 30s is the floor, Grok is the row, at 4 to 6 credits a second. If 8s 4K dialogue is the floor and you want Veo’s physics, Veo starts at 64. Fast at 20 is not a Veo discount. It is an LTX 4K length sticker.

Pro at 29 credits: 4K, 6 / 8 / 10 seconds

The Pro card: audio true, text-to-video, 6 / 8 / 10 seconds, 4K, 29 credits. Description: professional text-to-video with LTXV2. Shorter menu. Same 4K flag. Nine credits more.

Use Pro when:

The ship length is 6, 8, or 10 seconds, 4K, native audio, and you want the Pro row on that file.
You already drafted on Fast at 6s or 8s and the sentence held. Promoting is a nine-credit hero spend, not a first try.
You do not need 12–20 seconds. Paying Pro and then asking for 20s will not grow the card.

When Pro is the wrong pick:

You need 12–20 seconds. Stay on Fast. Pro will not stretch.
You are still finding the prompt. Twenty-nine credits is cheap next to Veo and still more than a wasted Fast take. Draft at 20.
You needed Veo, not LTX. Pro at 29 is not Veo at 64. If the shot is Veo-shaped — cinematic physics, always-on dialogue you would still send to Veo if LTX were free — pay 64. Do not grade Pro until it “feels like Veo.”

Veo 3.1 is 64 credits for 4 / 6 / 8s 4K native audio (32 a second with sound on). LTX Pro is 29 credits for 6 / 8 / 10s 4K native audio (20 a second at 4K). Thirty-five credits is the gap between the stickers. It is worth paying 64 when the file has to be Veo. It is theatre when the file has to be 4K and talking and ten seconds, and LTX is allowed. Honesty about the family is the pick.

Pixverse 5.6 talks from 28 credits, 1080p, 5 / 8 / 10s, and a full job runs up to 240. LTX Pro talks from 29, 4K, 6 / 8 / 10s, and a full job runs up to 192. If you landed on Pixverse 5.6 because you needed a talking 10-second take, look at this 4K row before you pay.

Cheap versus Pro, not a duration upgrade

The trap is treating Pro as the longer, fancier Fast. The menus go the other way. Fast owns 12–20s. Pro owns a 6 / 8 / 10s 4K pass at +9 credits. Pick Pro for polish on a short 4K talking take. Pick Fast for length, for drafts, and for 4K holds Veo cannot do.

Production order:

Write the length. If it is 12–20s, Fast only.
Write the family. If it must be Veo, leave. If 4K LTX is allowed, stay.
Draft on Fast at 6s or 8s at SD/HD, 4 credits a second.
Ship Fast if the draft is the master.
Rerun on Pro at 29 only for the 6 / 8 / 10s hero you will actually run.

Native audio is on for both. Write speech or none. Captions after the take. The AI caption generator is the burn-in. A 20-second Fast line that autoplays mute is a caption job. Captions for silent autoplay if the feed will never unmute.

If the cut needs 20 seconds, you are on Fast. If the cut is a 10-second 4K talking hero you already drafted, you can afford Pro’s 20 credits a second at 4K.

What neither LTX row is

Neither row is Veo. Veo 3.1 is 64 credits for 4 / 6 / 8s 4K native audio. LTX Fast at 20 and LTX Pro at 29 are LTX takes. If the shot is Veo-shaped — cinematic physics, always-on dialogue you would still send to Veo if LTX were free — pay 64. Do not grade a 29-credit Pro file until it “feels like Veo.”

Neither row is I2V. A still that must remain frame one belongs on Wan, Kling O3 I2V, or Veo first-last. Fast and Pro will invent the plate from a sentence.

Neither row is 4 seconds. Fast’s floor is 6s. Veo has 4s. A bumper that has to be four seconds is not an LTX job.

Neither row is 30 seconds. Fast stops at 20. Grok Imagine Video starts at 24 credits, 720p, up to 30s. If 30s is the floor, Grok. If 4K is the floor, Fast to 20s.

Article 50 applies to photoreal people in either take. Twenty credits does not exempt a generated face. Label at first exposure for EU audiences since 2 August 2026.

Sora 2 T2V was 32 credits, 720p, up to 20s, native audio. The Sora API shuts 24 September 2026 (OpenAI Help Centre, September 2026). A leftover 20-second talking brief at higher resolution is closer to LTX Fast at 13 credits a second at 4K than to Veo’s 8s at 32 a second with sound. Map length first, then family.

The AI video generator is the launcher. One bill. Two LTX T2V doors. The cheap one is longer. The Pro one is shorter and nine credits more.

Run the 4K door that matches the length in Versely.

FAQ

Does LTX Pro go to 20 seconds?

No. 6, 8, or 10. 12–20 seconds is LTX 2.3 Fast at 20 credits.

Is Fast 4K or is 4K only on Pro?

Both published cards are 4K. Fast is not a 720p draft of Pro. It is a 20-credit row with a 4K band and a longer menu.

When is Veo 3.1 still the pick at 64 credits?

When the shot is Veo-shaped: 4 / 6 / 8s cinematic you would still send to Veo if LTX were free. LTX Pro at 29 is not a Veo substitute. It is an LTX Pro 4K take.