What is a keyframe in animation?

The key to any animation is animated movement - the clue’s in the name. And to achieve this, animators use keyframes to guide the movement between two different images or illustrations. 

The development of keyframes has been an absolute lifesaver for animators who, previously, had to draw every single frame one at a time. Now, they can simply insert keyframes in specialist animation & motion design software, and the technology will create the movement for them. Think of the months (literally, some hand-drawn animations would require months of careful step-by-step drawing) saved in the animation process. In this article, we’ll show you what keyframes are, when keyframing needs to be used and the different types of keyframes out there. Keep reading to find out more about animation 1-0-1.


What is a keyframe in animation?

If you are totally unfamiliar with the world of animation, we may as well be speaking French right now. What on earth are keyframes, and how exactly do they give animations their movement? Keyframes are, in essence, an animator’s signposts. They direct the animation software, telling it what images will be moving, how they will be moving, what speed they will be moving at, and when the movement will stop. Animators use a keyframe to mark the start and end of an action. 

Let’s take an example of a simple animation, created using keyframes. Say we wanted to create an animation of a cat closing its eyes: 


  • Firstly, we would create two blank keyframes, with a number of ordinary blank frames in the middle. 
  • If you wanted the animation to last 0.5 seconds, with a frame speed of 30 fps, then you would create two blank keyframes, with 13 blank frames in the middle. 
  • In the first blank keyframe, you would add an illustration of a cat, with its eyes open. 
  • Then, in the second blank keyframe, insert an illustration of the same cat, but now with its eyes closed. 


In this example, you can see how the keyframes work by marking the start and the end of the movement that you are animating. Once the software knows where the animation will start and end, it fills in the gaps for you. It does this by using the frames in the middle to transition gradually from one keyframe to another, thereby creating the movement. The differences between the two values are registered, and the software takes the viewer from one image to another, by using the frames in the middle to make that change bit by bit. The result, for the viewer, is one smooth transition of movement.  You can use keyframing techniques to create any type of movement, including character movements, transitions, changing scale, rotating, and so on. 

Then, if you want to make the cat complete another movement, you create another keyframe after the second keyframe that you created (containing the drawing of the cat with its eyes closed). This third keyframe could contain, for example, the cat poking its tongue out. To create this movement in your animation, you insert a drawing of the cat with its tongue out in the third keyframe. Then, the software will create the transition movement between the second and third keyframes. Once you play the whole thing back, you’ll see your cat close its eyes, and then stick its tongue out. Pretty neat, right?


Why are keyframes important?

Animators use keyframes as their control points. Rather than creating the movement themselves, drawing it out bit by bit, they break down their planned animation in terms of a number of start and end points. For example, rather than thinking that they want an animation of a cat (can you tell I’m a cat person?) that moves around a room. They approach the animation process with a series of start and end points in mind. It’s a completely different approach to animation - you have to put a lot of trust in the computer! But, the benefits of this modern, tech-aided approach are fantastic. 

The top 6 reasons why keyframes are important (and incredibly useful!) are:


  1. They achieve a higher quality of animation. Keyframes produce sleek animated movements, while minimising the risk of any clunkiness or jolting movements (which can arise if the drawings used contain any slight differences). 
  2. They make the process far quicker. Rather than having to draw hundreds or thousands of individual frames, the animator only has to create a handful of keyframes - their workload is just a fraction of the amount!
  3. It’s far easier for the animator to keep track of the animation. When the animator overviews the keyframes, this allows them to immediately see where they are currently at in the animating process (rather than having to follow individual drawings one by one, and calculate what needs to be drawn next). 
  4. They provide the best of both worlds for hand-drawn animations. This process maximises speed, without losing the charming, personal effect that makes hand-drawn animations so popular. 
  5. They facilitate a huge range of animated movements. Keyframes and animation software can be used to create a vast array of different movements, bringing any idea to life quickly, to a highly professional finish. 
  6. Changes are a lot easier to make. If you want to change a movement, give the animation a different change of course, or another feature, this editing stage is infinitely easier, as you only need to tweak a couple of keyframes (rather than 100 individual frames, one by one). 

4 different kinds of keyframes in animation

There are 4 main types of keyframes used in animation. The main differences between each of these keyframe interpolations are the appearance and effect of the movement that they create.  Below, we’ll name these 4 different kinds of keyframe animation, and explain the specific effects that each one achieves. 

Linear

Linear keyframes are the most basic form of keyframe animation. They create a very simple, straight movement between two keyframes. The change between the two keyframes occurs at a uniform speed, in one single direction. An example of a linear keyframe would be moving a word across a screen. The word could move (for example) from the right to the left of the page, at an even speed, following a straight line, without the word changing in style or pace. As you can imagine, this kind of animation isn’t very attention-grabbing. So, it’s not often seen in animations created by professional animators (they tend to exhibit their skills in more dynamic animation styles). 

Auto Bezier

While linear keyframes are known for their more uniform, mechanical movements, Auto Bezier keyframes allow for a far smoother transition between two keyframes. With a few clicks, animators can convert a linear keyframe into an Auto Bezier keyframe. When this is requested, the software will generate and introduce curves to the keyframe transition. These curves give the moving image a smoother movement, making it a lot more pleasing to watch. 

Continuous Bezier

As you can see, there are two types of bezier keyframes - Auto Bezier and Continuous Bezier. ‘Bezier’ indicates that the animator has control of the movement curve between the two keyframes. They can adjust both the value graphs and the motion path of the moving image. 
While Auto Bezier keyframing is created automatically, Continuous Bezier keyframes give animators full manual control. Using this keyframe technique, the animator will be able to give the animation a far softer, more natural movement. The animator can also vary the movement throughout the transition, making the movement far more realistic. For example, if the animation was of a frog snapping its tongue forward, then the animator can make the first part of the movement faster than the second half, as the frog’s tongue lands on its target. 

Hold

Basically, a hold keyframe keeps the illustration on hold. It freezes the chosen illustration in place, until the end of that keyframe sequence. Then, movement resumes when the next transition starts. This animation technique can be used to create a number of effects, including freezing the animation, giving the reader a moment to read a piece of text, or giving a more jumpy style to the animation. 

Why work with a 2D animation studio like OK Social?

Although keyframes make the animation process a lot speedier, this doesn’t mean that it’s a case of a quick sketch and a couple of clicks! When it comes to creating a sleek, modern and engaging animation, the help of a professional animation agency is still invaluable.

OK Social is a professional animation studio, offering bespoke animations to businesses across a multitude of sectors. Our talented team of animators have worked alongside clients to create animations spanning everything from Capita’s onboarding explainer animation to Indie Bay Snacks’ product launch animation. By working with us, businesses can enjoy complete creative flexibility, aided by the help of professional animators. Our animators will give your animation a bold design that stands out in the marketplace; a high level of engagement, which achieves your KPIs; and a new piece of content that perfectly aligns with your brand image.

We will work with you on a one-to-one basis, to ensure your bespoke business animation ticks all of your boxes. To find out more about our professional animation agency, get in touch with the OK Social team today.

We’d love to talk about your new project.
You can reach us at hello@oksocial.co.uk