# How to choose an AI video generator Compare AI video tools on the six things that decide your result before you compare price: input type, clip length, resolution, watermark rules, commercial-use terms and total monthly cost. Updated 2026-11-13. Also on the [web page](https://aivideogen.fyi/guides/how-to-choose-an-ai-video-generator). AI video tools differ more than their landing pages suggest. Two tools that both say "text to video" can bill in different units, cap clips at different lengths and give you different rights to the result. Work through these six checks in order. Do not start with price. ## 1. Name the job, not the tool Write one sentence that says what the video must do. "A 30-second product ad for Instagram" is a job. "Make a video" is not. The job decides the input type you need, the length you need and whether you need an avatar, a generative model or a plain editor. If the job is presenter-style narration, look at avatar tools. If it is a product shot moving through a scene, look at image-to-video tools. If it is cutting existing footage into vertical clips, look at clip makers and editors. The category pages on this site group tools the same way. ## 2. Check what goes in and what comes out Each tool accepts different inputs. Some take only a text prompt. Some animate a still image. Some edit footage you already shot. Some add voiceover or music. Match the input you actually have. If you only have a script, a text-to-video or avatar tool fits. If you have product photos, an image-to-video tool fits better. On the output side, check three numbers on the vendor's own page: the longest clip it states, the highest resolution it states, and whether it exports the format your channel needs. A tool that makes beautiful 5-second clips will not finish a 60-second ad in one piece. ## 3. Read the watermark and free-plan rules Free tiers are where the differences hide. On the pricing pages we checked on 2026-11-13: - HeyGen's free plan gives 3 videos a month, watermarked, up to 1 minute each. - Synthesia's Basic plan gives 500 credits a month and videos carry a Synthesia watermark. - Pika's free plan has no watermark, but paid plans add a commercial license. - Runway's free plan gives 125 one-time credits, not a monthly allowance. A watermark on a client deliverable is usually a deal-breaker. A free plan you can only test once is different from a free plan you can publish from. Write down which rule applies to you before you compare prices. ## 4. Check commercial-use terms before you fall in love "You can publish this" and "you own this" are different claims. Some vendors license commercial use only on paid plans. Some reserve rights over inputs you upload. Read the vendor's terms page, not the marketing page, and record what it says. Each listing links to the vendor's own site, where the current terms are published. ## 5. Cost the real monthly volume Most tools bill in credits, minutes or clips. Convert your plan to cost per finished video before you compare. Pika's pricing page gives a worked example: on Starter, a 5-second 720p clip costs about 122 credits, around $2.03. Runway prices Gen-4.5 generations at 60 credits per 5 seconds. HeyGen sells credit tiers where 1,000 credits a month costs $49 and 100,000 credits costs $4,300. If you will make 20 clips a month, a cheap per-clip rate wins. If you will make two long videos a month, a flat subscription with a high credit pool may win. The cost estimator on this site does this arithmetic for you. ## 6. Test on your own material Every vendor demo is the best case. Before you subscribe, run your real script, your real product image and your real target length through the free tier or trial. Score three things: does the output match the brief, how many tries did it take, and does the export meet your channel's specs. Two or three tries on your own material tells you more than any comparison chart. ## A short decision order 1. Job and input type first. 2. Output length, resolution and format second. 3. Watermark and commercial-use terms third. 4. Monthly cost at your real volume fourth. 5. Trial on your own material last. This order keeps you from buying a powerful tool that cannot do your job, or a cheap tool whose free plan cannot ship your video. ## Sources - [Runway pricing (fetched 2026-11-13)](https://runwayml.com/pricing) - [Pika pricing (fetched 2026-11-13)](https://pika.art/pricing) - [HeyGen pricing (fetched 2026-11-13)](https://www.heygen.com/pricing) - [Synthesia pricing (fetched 2026-11-13)](https://www.synthesia.io/pricing) ## Questions ### Should I pick the tool with the best demo videos? Demo videos show the best case. Test the tool on your own script, your own product photos and your target length before you pay. ### Is the cheapest plan the cheapest option? Not always. Credit systems, per-clip limits and add-ons can make a low monthly price cost more than a higher flat plan at your volume. ### Do I need an API? Only if you plan to generate video inside your own product or workflow. Most buyers should start with the web app.