# Source: https://docs.datadoghq.com/profiler/compare_profiles.md

---
title: Compare Profiles
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: Docs > Continuous Profiler > Compare Profiles
---

# Compare Profiles

The Continuous Profiler can compare two profiles or profile aggregations with each other to help you identify code performance improvements, regressions, and structural changes. You can compare a profile with:

- Profiles taken at a different time,
- An average of the service's profiles over time, or
- Profiles with a different set of Datadog tags (for example, environment, version, or data center).

This helps you see if the service is taking more or less time, using more or less memory, making more or fewer allocations, throwing more or fewer exceptions, or involving more or less code and calls than it was in the past.

## Comparison scenarios{% #comparison-scenarios %}

Comparisons work best when the application is experiencing a similar workload (total requests) as it was in the past.

Some common scenarios to use comparison are:

- Comparing two latest deployments. For example, verify if the latest deployed fix lowers the number of memory allocations your method makes.

- Comparing two distinct time periods. For example, calculate the CPU consumption for today compared to the past week. What methods get better or worse in terms of CPU consumption?

- Comparing two different sets of tags. For example, compare profiles between different environments, availability zones, pods, canaries, or other custom Datadog tags.

## Accessing the comparison view{% #accessing-the-comparison-view %}

You can open different types of comparisons from different places in the UI.

### Comparing different time periods{% #comparing-different-time-periods %}

Go to **[APM > Profiles > Comparison](https://app.datadoghq.com/profiling/comparison)** and select a service to view its profiles over two distinct time periods.

{% video
   url="https://datadog-docs.imgix.net/images/profiler/compare_time_period.mp4" /%}

Select the metric you want to compare (the list of available metrics depends on the programming language). This allows you to correlate different performance issues, for example, by checking for memory allocation spikes while investigating a CPU profile.

Take note of the legend colors, which show:

- Deepening shades of red for methods that take more time in profile B.
- Deepening shades of green for methods that take less time in profile B.
- Purple for methods that are only in profile A.
- Blue for methods that are only in profile B.

These colors help you identify structural changes in your code between versions, time ranges, or canaries, and how they affect performance.

{% image
   source="https://datadog-docs.imgix.net/images/profiler/compare_legend.8c12ff459d95b440fb89240f7bae601d.png?auto=format"
   alt="Legend for profile comparison." /%}

Hover over methods in the profile to see specific metrics about the methods that are taking more or less time, or making fewer or more allocations, than in the compared profile.

{% image
   source="https://datadog-docs.imgix.net/images/profiler/compare_tooltip.1b30d77a97ac054ee0cdb4506e57a432.png?auto=format"
   alt="Hover over a method in the profile to see metrics comparison" /%}

### Comparing a profile to a previous time period{% #comparing-a-profile-to-a-previous-time-period %}

To compare a profile you are viewing against a different time period or a specific profile:

1. From any single profile view, click **â Compare** to open the comparison view.

1. The comparison view opens with your selected profile set as Profile B (the comparison target).

1. For Profile A (the baseline), select an aggregation time frame and tags, or provide a specific profile ID.

1. Select the metric you want to compare (the list of available metrics depends on the programming language). This is useful for correlating performance, for example, by checking for allocation spikes while investigating a CPU profile.

{% video
   url="https://datadog-docs.imgix.net/images/profiler/compare_single_profile_traces.mp4" /%}

### Comparing recent versions{% #comparing-recent-versions %}

On the **Explorer** view, select a service to see its aggregated profile for a particular metric (for example, wall time) over the selected time frame. Then click **Compare To** to compare it to the aggregated profile of another version.

{% video
   url="https://datadog-docs.imgix.net/images/profiler/compare_version.mp4" /%}

## Further reading{% #further-reading %}

- [Enable continuous profiler for your application](https://docs.datadoghq.com/profiler/enabling)
- [Getting Started with Profiler](https://docs.datadoghq.com/getting_started/profiler)
- [Introducing always-on production profiling in Datadog](https://www.datadoghq.com/blog/introducing-datadog-profiling/)
- [Compare and optimize your code with Datadog Profile Comparison](https://www.datadoghq.com/blog/code-optimization-datadog-profile-comparison/)
- [How we optimized our Akka application using Datadog's Continuous Profiler](https://www.datadoghq.com/blog/engineering/how-we-optimized-our-akka-application-using-datadogs-continuous-profiler/)