diff --git a/frontend/src/lib/components/FlowBuilder.svelte b/frontend/src/lib/components/FlowBuilder.svelte
index 52431ee1e8..0a1fd73f79 100644
--- a/frontend/src/lib/components/FlowBuilder.svelte
+++ b/frontend/src/lib/components/FlowBuilder.svelte
@@ -85,9 +85,9 @@
 	import { Triggers } from './triggers/triggers.svelte'
 	import {
 		SplitPanesLayout,
-		setSplitPanesLayoutContext,
-		type PanesLayout
+		setSplitPanesLayoutContext
 	} from './splitPanes/SplitPanesLayout.svelte'
+	import type { PanesLayout } from './splitPanes/types'
 	import { setTabStateContext, TabsState } from './common/tabs/tabsState.svelte'
 
 	export let initialPath: string = ''
diff --git a/frontend/src/lib/components/common/tabs/Tabs.svelte b/frontend/src/lib/components/common/tabs/Tabs.svelte
index 2c7eeb5c7d..90691e0b4e 100644
--- a/frontend/src/lib/components/common/tabs/Tabs.svelte
+++ b/frontend/src/lib/components/common/tabs/Tabs.svelte
@@ -66,7 +66,6 @@
 
 	if (id) {
 		tabsState = getTabStateContext()
-		console.log('dbg tabsState', tabsState)
 		const tabState = tabsState?.getSelected(id)
 		if (tabState) {
 			selected = tabState
diff --git a/frontend/src/lib/components/flows/FlowEditor.svelte b/frontend/src/lib/components/flows/FlowEditor.svelte
index 49a62bf28e..87db48e51f 100644
--- a/frontend/src/lib/components/flows/FlowEditor.svelte
+++ b/frontend/src/lib/components/flows/FlowEditor.svelte
@@ -46,8 +46,8 @@
 		$copilotCurrentStepStore !== undefined ? 'border-gray-500/75' : ''
 	)}
 >
-	<Splitpanes id="flow-editor">
-		<Pane minSize={15} class="h-full relative z-0" index={0} defaultSize={60}>
+	<Splitpanes id="flow-editor" defaultSize={[60, 40]}>
+		<Pane minSize={15} class="h-full relative z-0" index={0}>
 			<div class="grow overflow-hidden bg-gray h-full bg-surface-secondary relative">
 				{#if loading}
 					<div class="p-2 pt-10">
@@ -69,7 +69,7 @@
 				{/if}
 			</div>
 		</Pane>
-		<Pane class="relative z-10" index={1} defaultSize={40}>
+		<Pane class="relative z-10" index={1}>
 			{#if loading}
 				<div class="w-full h-full">
 					<div class="block m-auto pt-40 w-10">
diff --git a/frontend/src/lib/components/flows/content/FlowModuleComponent.svelte b/frontend/src/lib/components/flows/content/FlowModuleComponent.svelte
index 90986d3053..a88ecf4f57 100644
--- a/frontend/src/lib/components/flows/content/FlowModuleComponent.svelte
+++ b/frontend/src/lib/components/flows/content/FlowModuleComponent.svelte
@@ -376,8 +376,8 @@
 				{/if}
 
 				<div class="min-h-0 flex-grow" id="flow-editor-editor">
-					<Splitpanes id={`flow-editor-split-${flowModule.id}`} horizontal>
-						<Pane minSize={10} class="relative" index={0} defaultSize={panesSizes[0]}>
+					<Splitpanes id={`flow-editor-split-${flowModule.id}`} horizontal defaultSize={panesSizes}>
+						<Pane minSize={10} class="relative" index={0}>
 							{#if flowModule.value.type === 'rawscript'}
 								{#if !noEditor}
 									{#key flowModule.id}
@@ -453,9 +453,9 @@
 								{/key}
 							{/if}
 						</Pane>
-						<Pane minSize={20} index={1} defaultSize={panesSizes[1]}>
-							<Splitpanes id={`flow-editor-step-input-${flowModule.id}`}>
-								<Pane minSize={36} index={0} defaultSize={selected === 'inputs' ? 100 : 50}>
+						<Pane minSize={20} index={1}>
+							<Splitpanes id={`flow-editor-step-input-${flowModule.id}`} defaultSize={[50, 50]}>
+								<Pane minSize={36} index={0}>
 									<Tabs bind:selected id={`flow-editor-step-input-${flowModule.id}`}>
 										{#if !preprocessorModule}
 											<Tab value="inputs">Step Input</Tab>
@@ -784,7 +784,7 @@
 									</div>
 								</Pane>
 								{#if selected === 'test'}
-									<Pane minSize={20} index={1} defaultSize={50}>
+									<Pane minSize={20} index={1}>
 										<ModulePreviewResultViewer
 											lang={flowModule.value['language'] ?? 'deno'}
 											{editor}
diff --git a/frontend/src/lib/components/flows/propPicker/PropPickerWrapper.svelte b/frontend/src/lib/components/flows/propPicker/PropPickerWrapper.svelte
index d025f72420..a260b45fba 100644
--- a/frontend/src/lib/components/flows/propPicker/PropPickerWrapper.svelte
+++ b/frontend/src/lib/components/flows/propPicker/PropPickerWrapper.svelte
@@ -104,11 +104,11 @@
 	<Splitpanes
 		class={$propPickerConfig ? 'splitpanes-remove-splitter' : ''}
 		id={`prop-picker-wrapper-${moduleId}`}
+		defaultSize={[60, 40]}
 	>
 		<Pane
 			index={0}
 			minSize={20}
-			defaultSize={60}
 			class={twMerge('relative !transition-none ', noPadding ? '' : 'p-2')}
 		>
 			<slot />
@@ -116,7 +116,6 @@
 		<Pane
 			index={1}
 			minSize={20}
-			defaultSize={40}
 			class="!transition-none z-1000 {$propPickerConfig ? 'ml-[-1px]' : ''} {paneClass}"
 		>
 			<AnimatedButton
diff --git a/frontend/src/lib/components/splitPanes/Pane.svelte b/frontend/src/lib/components/splitPanes/Pane.svelte
index afe8f6dfc9..8c3a34d11e 100644
--- a/frontend/src/lib/components/splitPanes/Pane.svelte
+++ b/frontend/src/lib/components/splitPanes/Pane.svelte
@@ -1,32 +1,25 @@
 <script lang="ts">
 	import { Pane } from 'svelte-splitpanes'
-	import { getSplitPanesLayout } from './SplitPanesLayout.svelte'
 	import type { Snippet } from 'svelte'
-	import { type ComponentProps, getContext, onDestroy, onMount } from 'svelte'
+	import { getContext, onMount, type ComponentProps } from 'svelte'
+	import type { SplitPanesContext } from './types'
 
 	type SplitpanesProps = ComponentProps<Pane>
 
-	type Props = SplitpanesProps & {
+	export type Props = SplitpanesProps & {
 		index: number
-		defaultSize: number
 		children?: Snippet
 	}
 
-	let { index, defaultSize, children, ...rest }: Props = $props()
+	let { index, children, ...rest }: Props = $props()
 
-	const splitPanesId = getContext<string>('splitPanesId')
-
-	const splitPanesLayout = getSplitPanesLayout()
+	const { sizes, setActivePane } = getContext<SplitPanesContext>('splitPanesContext') ?? {}
 
 	onMount(() => {
-		splitPanesLayout?.mountPane(splitPanesId, index, defaultSize)
-	})
-
-	onDestroy(() => {
-		splitPanesLayout?.unmountPane(splitPanesId, index)
+		setActivePane(index)
 	})
 </script>
 
-<Pane size={splitPanesLayout?.layout[splitPanesId]?.[index]?.size ?? defaultSize} {...rest}>
+<Pane size={sizes?.(index)} {...rest}>
 	{@render children?.()}
 </Pane>
diff --git a/frontend/src/lib/components/splitPanes/SplitPanesLayout.svelte.ts b/frontend/src/lib/components/splitPanes/SplitPanesLayout.svelte.ts
index fe88020274..f4972232e1 100644
--- a/frontend/src/lib/components/splitPanes/SplitPanesLayout.svelte.ts
+++ b/frontend/src/lib/components/splitPanes/SplitPanesLayout.svelte.ts
@@ -1,14 +1,8 @@
 import { setContext, getContext, tick } from 'svelte'
+import type { Pane, PanesLayout } from './types'
 
 const KEY = 'splitPanesLayout'
 
-export type Pane = {
-	size: number | undefined
-	active: boolean
-}
-
-export type PanesLayout = Pane[]
-
 export class SplitPanesLayout {
 	#layout: Record<string, PanesLayout> = $state({})
 	#changeCb: (() => void) | undefined = undefined
@@ -28,30 +22,27 @@ export class SplitPanesLayout {
 		this.#changeCb?.()
 	}
 
-	mountPane(layoutId: string, paneIndex: number, defaultSize: number) {
-		if (!this.#layout[layoutId]) {
-			this.#layout[layoutId] = [{ size: defaultSize, active: true }]
-		} else if (this.#readyPanes[layoutId]) {
-			// Ensure array is long enough
-			while (this.#layout[layoutId].length <= paneIndex) {
-				this.#layout[layoutId].push({ size: undefined, active: false })
-			}
-			this.#layout[layoutId][paneIndex].active = true
-			this.#layout[layoutId][paneIndex].size = this.#layout[layoutId][paneIndex].size ?? defaultSize
-			this.#scalePanes(layoutId, paneIndex)
+	addPane(layoutId: string, paneIndex: number) {
+		if (!this.#readyPanes[layoutId] || !this.#layout[layoutId][paneIndex].size) {
+			return
 		} else {
-			// Ensure array is long enough
-			while (this.#layout[layoutId].length <= paneIndex) {
-				this.#layout[layoutId].push({ size: undefined, active: false })
-			}
-
-			const currentPane = this.#layout[layoutId][paneIndex]
-			currentPane.active = true
-			currentPane.size = currentPane.size ?? defaultSize
+			this.#layout[layoutId][paneIndex].active = true
+			this.#scalePanes(layoutId, paneIndex)
 		}
 		this.#changeCb?.()
 	}
 
+	setPanes(layoutId: string, panes: Pane[]) {
+		if (!this.#layout[layoutId]) {
+			this.#layout[layoutId] = []
+		}
+
+		this.#layout[layoutId] = panes
+		this.#scalePanesTo100(layoutId)
+		this.#readyPanes[layoutId] = true
+		this.#changeCb?.()
+	}
+
 	#scalePanes(layoutId: string, paneIndex: number) {
 		// Scale other active panes while keeping the current pane size
 		const otherPanesTotal = this.#layout[layoutId]
@@ -70,6 +61,7 @@ export class SplitPanesLayout {
 		const activePanesTotal = this.#layout[layoutId]
 			.filter((pane) => pane.active)
 			.reduce((sum, pane) => sum + (pane.size ?? 0), 0)
+
 		if (activePanesTotal > 0) {
 			const scale = 100 / activePanesTotal
 			this.#layout[layoutId] = this.#layout[layoutId].map((pane) =>
@@ -78,10 +70,10 @@ export class SplitPanesLayout {
 		}
 	}
 
-	async unmountPane(layoutId: string, paneIndex: number) {
-		// Wait for the dom refresh to avoid update in the case the splitpane has been removed
+	async removePane(layoutId: string, paneIndex: number) {
+		// Wait for the dom refresh to avoid update in the case the splitpane has been removed completly
 		await tick()
-		if (this.#readyPanes[layoutId]) {
+		if (this.#readyPanes[layoutId] && this.#layout[layoutId][paneIndex].active) {
 			this.#layout[layoutId][paneIndex].active = false
 			this.#scalePanesTo100(layoutId)
 		}
@@ -98,12 +90,6 @@ export class SplitPanesLayout {
 		this.#changeCb?.()
 	}
 
-	handleSplitPaneReady(layoutId: string) {
-		this.#readyPanes[layoutId] = true
-		this.#scalePanesTo100(layoutId)
-		this.#changeCb?.()
-	}
-
 	handleSplitPaneDestroy(layoutId: string) {
 		this.#readyPanes[layoutId] = false
 		this.#changeCb?.()
diff --git a/frontend/src/lib/components/splitPanes/Splitpanes.svelte b/frontend/src/lib/components/splitPanes/Splitpanes.svelte
index b0ec6e6ff3..9886763f2e 100644
--- a/frontend/src/lib/components/splitPanes/Splitpanes.svelte
+++ b/frontend/src/lib/components/splitPanes/Splitpanes.svelte
@@ -1,30 +1,40 @@
 <script lang="ts">
 	import { Splitpanes } from 'svelte-splitpanes'
 	import { getSplitPanesLayout } from './SplitPanesLayout.svelte'
-	import { onDestroy, onMount, setContext, type Snippet } from 'svelte'
+	import { onDestroy, setContext, type Snippet } from 'svelte'
 	import type { ComponentProps } from 'svelte'
+	import type { Pane, SplitPanesContext } from './types'
 
 	type SplitpanesProps = ComponentProps<Splitpanes>
 
 	type Props = SplitpanesProps & {
+		defaultSize: number[]
 		id: string
 		children?: Snippet
 	}
 
-	let { id, children, ...rest }: Props = $props()
-	let timeout: ReturnType<typeof setTimeout> | undefined = undefined
-
-	setContext<string>('splitPanesId', id)
-
 	const splitPanesLayout = getSplitPanesLayout()
 
-	onMount(() => {
-		splitPanesLayout?.handleSplitPaneReady(id)
+	let { id, children, defaultSize, ...rest }: Props = $props()
+	const sizes = $derived(splitPanesLayout?.layout[id]?.map((pane) => pane.size ?? 0) ?? [])
+
+	setContext<SplitPanesContext>('splitPanesContext', {
+		sizes: (index: number) => sizes[index],
+		setActivePane: (index: number) => {
+			panes[index].active = true
+		}
 	})
 
+	function initPane(defaultSize: number[]): Pane[] {
+		// Initialize all panes with default sizes
+		const panes = defaultSize.map((size, idx) => ({ size, active: false }))
+		return panes
+	}
+
+	let panes: Pane[] = $state(initPane(defaultSize))
+
 	onDestroy(() => {
 		splitPanesLayout?.handleSplitPaneDestroy(id)
-		clearTimeout(timeout)
 	})
 </script>
 
@@ -35,6 +45,15 @@
 			detail.map((d, index) => ({ size: d.size, index }))
 		)
 	}}
+	on:pane-add={({ detail }) => {
+		splitPanesLayout?.addPane(id, detail.index)
+	}}
+	on:pane-remove={({ detail }) => {
+		splitPanesLayout?.removePane(id, detail.removed.index)
+	}}
+	on:ready={() => {
+		splitPanesLayout?.setPanes(id, panes)
+	}}
 	{...rest}
 >
 	{@render children?.()}
diff --git a/frontend/src/lib/components/splitPanes/types.ts b/frontend/src/lib/components/splitPanes/types.ts
new file mode 100644
index 0000000000..103e29979b
--- /dev/null
+++ b/frontend/src/lib/components/splitPanes/types.ts
@@ -0,0 +1,11 @@
+export type Pane = {
+	size: number | undefined
+	active: boolean
+}
+
+export type PanesLayout = Pane[]
+
+export type SplitPanesContext = {
+	sizes: (index: number) => number | undefined
+	setActivePane: (index: number) => void
+}
diff --git a/frontend/src/routes/(root)/(logged)/flows/edit/[...path]/+page.svelte b/frontend/src/routes/(root)/(logged)/flows/edit/[...path]/+page.svelte
index cadf01914c..5b8f9a2286 100644
--- a/frontend/src/routes/(root)/(logged)/flows/edit/[...path]/+page.svelte
+++ b/frontend/src/routes/(root)/(logged)/flows/edit/[...path]/+page.svelte
@@ -16,7 +16,7 @@
 	import type { ScheduleTrigger } from '$lib/components/triggers'
 	import type { GetInitialAndModifiedValues } from '$lib/components/common/confirmationModal/unsavedTypes'
 	import type { Trigger } from '$lib/components/triggers/utils'
-	import type { PanesLayout } from '$lib/components/splitPanes/SplitPanesLayout.svelte'
+	import type { PanesLayout } from '$lib/components/splitPanes/types'
 
 	let version: undefined | number = undefined
 	let nodraft = $page.url.searchParams.get('nodraft')