diff --git a/packages/grafana-ui/src/components/Input/Input.tsx b/packages/grafana-ui/src/components/Input/Input.tsx
index 4f2eb4664b2..e24d961514c 100644
--- a/packages/grafana-ui/src/components/Input/Input.tsx
+++ b/packages/grafana-ui/src/components/Input/Input.tsx
@@ -43,7 +43,7 @@ export const Input = React.forwardRef<HTMLInputElement, Props>((props, ref) => {
   const styles = getInputStyles({ theme, invalid: !!invalid, width });
 
   return (
-    <div className={cx(styles.wrapper, className)}>
+    <div className={cx(styles.wrapper, className)} data-testid={'input-wrapper'}>
       {!!addonBefore && <div className={styles.addon}>{addonBefore}</div>}
 
       <div className={styles.inputWrapper}>
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/components/NestedQuery.tsx b/public/app/plugins/datasource/prometheus/querybuilder/components/NestedQuery.tsx
index 46f0e3cd5d0..5a7b92dcfa1 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/components/NestedQuery.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/components/NestedQuery.tsx
@@ -1,9 +1,10 @@
 import { css } from '@emotion/css';
 import { GrafanaTheme2, toOption } from '@grafana/data';
 import { EditorRows, FlexItem } from '@grafana/experimental';
-import { IconButton, Input, Select, useStyles2 } from '@grafana/ui';
+import { IconButton, Select, useStyles2 } from '@grafana/ui';
 import React from 'react';
 import { PrometheusDatasource } from '../../datasource';
+import { AutoSizeInput } from '../shared/AutoSizeInput';
 import { PromVisualQueryBinary } from '../types';
 import { PromQueryBuilder } from './PromQueryBuilder';
 
@@ -36,10 +37,10 @@ export const NestedQuery = React.memo<Props>(({ nestedQuery, index, datasource,
         />
         <div className={styles.name}>Vector matches</div>
 
-        <Input
-          width={20}
+        <AutoSizeInput
+          minWidth={20}
           defaultValue={nestedQuery.vectorMatches}
-          onBlur={(evt) => {
+          onCommitChange={(evt) => {
             onChange(index, {
               ...nestedQuery,
               vectorMatches: evt.currentTarget.value,
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderOptions.tsx b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderOptions.tsx
index 33bcc9ae8e4..a9f63a62f57 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderOptions.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderOptions.tsx
@@ -1,12 +1,13 @@
 import React, { SyntheticEvent } from 'react';
 import { EditorRow, EditorField } from '@grafana/experimental';
 import { CoreApp, SelectableValue } from '@grafana/data';
-import { Input, RadioButtonGroup, Select, Switch } from '@grafana/ui';
+import { RadioButtonGroup, Select, Switch } from '@grafana/ui';
 import { QueryOptionGroup } from '../shared/QueryOptionGroup';
 import { PromQuery } from '../../types';
 import { FORMAT_OPTIONS, INTERVAL_FACTOR_OPTIONS } from '../../components/PromQueryEditor';
 import { getQueryTypeChangeHandler, getQueryTypeOptions } from '../../components/PromExploreExtraField';
 import { getLegendModeLabel, PromQueryLegendEditor } from './PromQueryLegendEditor';
+import { AutoSizeInput } from '../shared/AutoSizeInput';
 
 export interface Props {
   query: PromQuery;
@@ -21,7 +22,7 @@ export const PromQueryBuilderOptions = React.memo<Props>(({ query, app, onChange
     onRunQuery();
   };
 
-  const onChangeStep = (evt: React.FocusEvent<HTMLInputElement>) => {
+  const onChangeStep = (evt: React.FormEvent<HTMLInputElement>) => {
     onChange({ ...query, interval: evt.currentTarget.value });
     onRunQuery();
   };
@@ -57,12 +58,12 @@ export const PromQueryBuilderOptions = React.memo<Props>(({ query, app, onChange
             </>
           }
         >
-          <Input
+          <AutoSizeInput
             type="text"
             aria-label="Set lower limit for the step parameter"
             placeholder={'auto'}
-            width={10}
-            onBlur={onChangeStep}
+            minWidth={10}
+            onCommitChange={onChangeStep}
             defaultValue={query.interval}
           />
         </EditorField>
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryLegendEditor.tsx b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryLegendEditor.tsx
index 3a9ba54a9a4..f5c920a0a09 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryLegendEditor.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryLegendEditor.tsx
@@ -1,8 +1,9 @@
 import React, { useRef } from 'react';
 import { EditorField } from '@grafana/experimental';
 import { SelectableValue } from '@grafana/data';
-import { Input, Select } from '@grafana/ui';
+import { Select } from '@grafana/ui';
 import { LegendFormatMode, PromQuery } from '../../types';
+import { AutoSizeInput } from '../shared/AutoSizeInput';
 
 export interface Props {
   query: PromQuery;
@@ -27,7 +28,7 @@ export const PromQueryLegendEditor = React.memo<Props>(({ query, onChange, onRun
   const mode = getLegendMode(query.legendFormat);
   const inputRef = useRef<HTMLInputElement | null>(null);
 
-  const onLegendFormatChanged = (evt: React.FocusEvent<HTMLInputElement>) => {
+  const onLegendFormatChanged = (evt: React.FormEvent<HTMLInputElement>) => {
     let legendFormat = evt.currentTarget.value;
     if (legendFormat.length === 0) {
       legendFormat = LegendFormatMode.Auto;
@@ -62,12 +63,12 @@ export const PromQueryLegendEditor = React.memo<Props>(({ query, onChange, onRun
     >
       <>
         {mode === LegendFormatMode.Custom && (
-          <Input
+          <AutoSizeInput
             id="legendFormat"
-            width={22}
+            minWidth={22}
             placeholder="auto"
             defaultValue={query.legendFormat}
-            onBlur={onLegendFormatChanged}
+            onCommitChange={onLegendFormatChanged}
             ref={inputRef}
           />
         )}
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.test.tsx b/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.test.tsx
new file mode 100644
index 00000000000..0e0ef42b541
--- /dev/null
+++ b/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.test.tsx
@@ -0,0 +1,51 @@
+import React from 'react';
+import { screen, render, fireEvent } from '@testing-library/react';
+import { AutoSizeInput } from './AutoSizeInput';
+
+jest.mock('@grafana/ui', () => {
+  const original = jest.requireActual('@grafana/ui');
+  const mockedUi = { ...original };
+
+  // Mocking measureText
+  mockedUi.measureText = (text: string, fontSize: number) => {
+    return { width: text.length * fontSize };
+  };
+
+  return mockedUi;
+});
+
+describe('AutoSizeInput', () => {
+  it('should have default minWidth when empty', () => {
+    render(<AutoSizeInput />);
+
+    const input: HTMLInputElement = screen.getByTestId('autosize-input');
+    const inputWrapper: HTMLDivElement = screen.getByTestId('input-wrapper');
+
+    fireEvent.change(input, { target: { value: '' } });
+
+    expect(input.value).toBe('');
+    expect(getComputedStyle(inputWrapper).width).toBe('80px');
+  });
+
+  it('should have default minWidth for short content', () => {
+    render(<AutoSizeInput />);
+
+    const input: HTMLInputElement = screen.getByTestId('autosize-input');
+    const inputWrapper: HTMLDivElement = screen.getByTestId('input-wrapper');
+
+    fireEvent.change(input, { target: { value: 'foo' } });
+
+    expect(input.value).toBe('foo');
+    expect(getComputedStyle(inputWrapper).width).toBe('80px');
+  });
+
+  it('should change width for long content', () => {
+    render(<AutoSizeInput />);
+
+    const input: HTMLInputElement = screen.getByTestId('autosize-input');
+    const inputWrapper: HTMLDivElement = screen.getByTestId('input-wrapper');
+
+    fireEvent.change(input, { target: { value: 'very very long value' } });
+    expect(getComputedStyle(inputWrapper).width).toBe('304px');
+  });
+});
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.tsx b/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.tsx
new file mode 100644
index 00000000000..a0223f596c7
--- /dev/null
+++ b/public/app/plugins/datasource/prometheus/querybuilder/shared/AutoSizeInput.tsx
@@ -0,0 +1,71 @@
+import { Input, measureText } from '@grafana/ui';
+import { Props as InputProps } from '@grafana/ui/src/components/Input/Input';
+import React, { useEffect } from 'react';
+export interface Props extends InputProps {
+  /** Sets the min-width to a multiple of 8px. Default value is 10*/
+  minWidth?: number;
+  /** Sets the max-width to a multiple of 8px.*/
+  maxWidth?: number;
+  /** onChange function that will be run on onBlur and onKeyPress with enter*/
+  onCommitChange?: (event: React.FormEvent<HTMLInputElement>) => void;
+}
+
+export const AutoSizeInput = React.forwardRef<HTMLInputElement, Props>((props, ref) => {
+  const { defaultValue = '', minWidth = 10, maxWidth, onCommitChange, onKeyDown, onBlur, ...restProps } = props;
+  const [value, setValue] = React.useState(defaultValue);
+  const [inputWidth, setInputWidth] = React.useState(minWidth);
+
+  useEffect(() => {
+    setInputWidth(getWidthFor(value.toString(), minWidth, maxWidth));
+  }, [value, maxWidth, minWidth]);
+
+  return (
+    <Input
+      {...restProps}
+      ref={ref}
+      value={value.toString()}
+      onChange={(event) => {
+        setValue(event.currentTarget.value);
+      }}
+      width={inputWidth}
+      onBlur={(event) => {
+        if (onCommitChange) {
+          onCommitChange(event);
+        }
+        if (onBlur) {
+          onBlur(event);
+        }
+      }}
+      onKeyDown={(event) => {
+        if (event.key === 'Enter' && onCommitChange) {
+          onCommitChange(event);
+        }
+        if (onKeyDown) {
+          onKeyDown(event);
+        }
+      }}
+      data-testid={'autosize-input'}
+    />
+  );
+});
+
+function getWidthFor(value: string, minWidth: number, maxWidth: number | undefined): number {
+  if (!value) {
+    return minWidth;
+  }
+
+  const extraSpace = 3;
+  const realWidth = measureText(value.toString(), 14).width / 8 + extraSpace;
+
+  if (minWidth && realWidth < minWidth) {
+    return minWidth;
+  }
+
+  if (maxWidth && realWidth > maxWidth) {
+    return realWidth;
+  }
+
+  return realWidth;
+}
+
+AutoSizeInput.displayName = 'AutoSizeInput';
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/shared/OperationParamEditor.tsx b/public/app/plugins/datasource/prometheus/querybuilder/shared/OperationParamEditor.tsx
index 3549b82a2ac..0befd0b5760 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/shared/OperationParamEditor.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/shared/OperationParamEditor.tsx
@@ -1,7 +1,8 @@
 import { SelectableValue, toOption } from '@grafana/data';
-import { Input, Select } from '@grafana/ui';
+import { Select } from '@grafana/ui';
 import React, { ComponentType } from 'react';
 import { QueryBuilderOperationParamDef, QueryBuilderOperationParamEditorProps } from '../shared/types';
+import { AutoSizeInput } from './AutoSizeInput';
 import { getOperationParamId } from './operationUtils';
 
 export function getOperationParamEditor(
@@ -20,18 +21,10 @@ export function getOperationParamEditor(
 
 function SimpleInputParamEditor(props: QueryBuilderOperationParamEditorProps) {
   return (
-    <Input
+    <AutoSizeInput
       id={getOperationParamId(props.operationIndex, props.index)}
-      defaultValue={props.value ?? ''}
-      onKeyDown={(evt) => {
-        if (evt.key === 'Enter') {
-          if (evt.currentTarget.value !== props.value) {
-            props.onChange(props.index, evt.currentTarget.value);
-          }
-          props.onRunQuery();
-        }
-      }}
-      onBlur={(evt) => {
+      defaultValue={props.value}
+      onCommitChange={(evt) => {
         props.onChange(props.index, evt.currentTarget.value);
       }}
     />