Ever catch yourself using words like felt, thought, or realised? These sneaky filter words can put a wall between your reader and your story. The good news? Spotting and trimming them is like discovering a hidden tool for making your writing stronger, sharper, and more immersive. This post shows you how to recognise filter words, when to keep them, and when to ditch them—so your scenes grab readers and don’t let go.

Here's what’s covered:

• What is a filter word?
• Examples of filter words
• What filter words do
• When to keep filter words

What is a Filter Word?

Filter words are terms like felt, saw, thought, realised, and heard that insert a subtle layer between your character’s experience and the reader’s perception of it. Instead of plunging your reader directly into the action or emotion, they act as a lens, filtering the scene through the character’s perspective. In other words, your readers look at your character rather than experience events through your character.

For example:

• She felt the cold air creep along her spine.
• Cold air crept along her spine.

By removing the filter, you bring immediacy and directness to your prose. But that doesn’t mean filter words should always be avoided—used sparingly, they can enhance introspection and reflection.

Examples of Filter Words

Filter words often relate to sensory perception or thought processes. Here are some common examples:

• Sensory: saw, heard, felt, noticed, smelled, tasted
• Thought processes: thought, wondered, realised, knew, believed, remembered, decided

A useful way to spot filter words is to identify pronouns, as filter words tend to follow immediately. These words indicate what a character is experiencing or thinking, but they can create a layer of distance between the reader and the scene. For instance:

• She noticed the clock ticking in the silence.
• The clock ticked in the silence.

What Filter Words Do

Filter words subtly distance the reader from the character’s experience. Instead of showing what’s happening, they tell the reader about it, creating a barrier to the immediacy of the story. In a genre like thriller, where tension and pace are crucial, this can weaken the impact of your writing.

Let’s explore the effect:

• She thought she heard a noise behind her, but it might have been her imagination.
• A noise came from behind her. Or was it just her imagination?

The first example explains the thought process, while the second plunges the reader directly into her uncertainty, creating more tension.

Across a paragraph, removing filter words can make a real difference to momentum:

With Filter Words:

She felt the cold air creep along her spine as she watched the shadow move across the hallway. She could hear her own breath quicken, sharp and shallow, as she realised she was no longer alone. Her fingers seemed to grip the doorframe, trembling slightly, as she thought about whether to scream or stay silent.

Without Filter Words:

Cold air crept along her spine, and a shadow slid across the hallway. Her breath quickened, sharp and shallow, and the realisation hit—she wasn’t alone. Her fingers gripped the doorframe, trembling, as she weighed whether to scream or stay silent.

Overusing filter words can also make your writing feel repetitive and unnecessarily wordy. By identifying and revising them, you can tighten your prose and bring readers closer to the action, which is particularly important when crafting suspenseful or high-stakes scenes.

When to Keep Filter Words

Not all filter words need to be cut. There are times when they serve a purpose, especially in moments of introspection, reflection, or when you want to highlight a character’s subjective experience.

For example:

• He realised he’d been holding his breath.
• I thought about running, but my legs wouldn’t move.
• She felt the weight of the decision settle on her shoulders.

In these cases, filter words help to slow the pace and bring the reader inside the character’s mind, which can add depth to your storytelling. The key is to use them intentionally and sparingly, choosing moments where reflection adds to the story rather than diluting it.

Final Thoughts

Recognising and managing filter words is a skill that can transform your writing. By stripping them away when they’re unnecessary and keeping them for moments of reflection or heightened emotion, you can create prose that’s vivid, immediate, and gripping—everything a great thriller needs to keep readers hooked. Start paying attention to filter words in your own writing, and you’ll soon see the difference they can make.