FabFilter Pro-L 2 true-peak limiter plug-in: features and spec-based rating

FabFilter’s Pro-L 2 is a true-peak limiter with eight limiting algorithms. It supports a loudness meter compliant with EBU R128 and other standards, linear-phase (a method that does not shift the timing of the sound) oversampling of up to 32x (processing finely inside to reduce distortion noise), dithering, and surround up to Dolby Atmos.

A limiter raises the overall volume of a song while preventing clipping (distortion). You use it at the last stage of finishing a song.

In this article we compare Pro-L 2 with 13 limiter plug-ins and rate how well it serves its purpose on three criteria. The basis is official manufacturer information.

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Image: from the FabFilter official press kit

Summary

Among the 13 limiter plug-ins, Pro-L 2 is rank S. The ranks run S, A, B and C, and S is the top. Averaging the scores for each criterion (out of 5, with the one criterion that matters most for the purpose counted double) gives 4.5.

Strengths

• Raising volume safely (5 points): it has what you need to prevent clipping and match the volume of streaming services.
• Choice of sound character (5 points): you can choose the character of the sound when raising the volume to suit the song.

Who it suits: people who want to match streaming loudness standards and also choose the character of the limiter.

Main features of Pro-L 2

Eight algorithms with different characters

A limiter sets a ceiling on the volume so the sound does not clip, and raises the overall volume of a song. Pro-L 2 has eight algorithms that act differently, from transparent to ones that add power. You can choose according to the genre of the song and how much louder you want it.

True peak and 32x oversampling

Digital sound can go over 0 dB between samples when a player turns it back into sound, which can cause clipping. True-peak limiting is a function that watches even the peaks between samples to keep the ceiling. Combined with oversampling of up to 32x (recalculating finely inside), it lets you finish a track for streaming safely.

A loudness meter to match streaming standards

It includes a loudness meter that follows standards such as EBU R128 and ITU-R BS.1770-4. When matching the loudness guidelines of a streaming service, you do not need to prepare another meter. With Unity Gain you can compare only the effect of the limiter at the original volume.

A display that shows the change in the sound

The waveform display shows where and by how much the volume was lowered, with numbers. There is also Audition Limiting, which lets you hear only the difference between input and output, so you can check by ear the part that was cut. Look-ahead, attack and release can also be set yourself.

Video: “Introduction to FabFilter Pro-L 2 Limiter” (official FabFilter YouTube channel; narration in English) Watch on YouTube

Where it is useful

• Finishing a completed song to match the loudness guidelines of a streaming service
• Setting the true peak to -1 dB so that the sound is less likely to clip when converted for streaming
• Using Unity Gain to check how much it is acting without being fooled by loudness

Rating by criterion

Raising volume safely: 5 / 5

We check whether it has features that prevent clipping and match the loudness standards of streaming services.

It has true-peak limiting, a loudness meter following EBU R128 and other standards, and oversampling of up to 32x.

Speed: 3 / 5

We check whether it has features that get you to a good setting quickly (automatic settings, easy-to-read meters and so on).

It has Unity Gain, which compares the effect of the limiter at the original volume. It has no AI automatic setting.

Choice of sound character: 5 / 5

We check whether you can choose the character of the sound when raising the volume (keeping the punch, keeping it transparent and so on).

You can choose from eight limiting algorithms with different characters.

How we score (Limiter plug-ins)

Criterion	Basis	5 pt	4 pt	3 pt	2 pt	1 pt
Raising volume safely	Features that prevent clipping and match the loudness standards of streaming services	True-peak limiting, loudness metering and oversampling are all included	Two of those	One of those	—	Not mentioned on the official page
Speed	How quickly you can reach a good setting	AI analyzes the song and sets everything automatically	—	Presets, or a function for comparing at matched loudness	Standard controls	—
Choice of sound character	The range of ways the limiter can act and shape the sound	Choose from eight or more algorithms	Besides a choice of styles, features that shape loudness feel or attack	A choice of styles	One type	—

Each criterion is scored from 1 to 5 on how well the product serves one goal: safely finishing a song at a volume suited to streaming. Scores follow the conditions in the table above, and the rank is based on an average in which "Raising volume safely" counts double. The basis is official manufacturer information. Sound quality and CPU load are not measured, so they are not scored; reviews from trade magazines are introduced in the articles for reference. Price is not part of the score. Features that cannot be confirmed from the manufacturer's or a retailer's description are scored as if absent. The "OBS (streaming)" column in the table shows whether the official page lists the VST2 format that the streaming software OBS Studio can use (○). OBS does not support the VST3 format. It is not part of the score.

Pro-L 2 screens and images

Image: from the FabFilter official press kit

Trade-magazine review (for reference, not part of the score)

We summarized the main points from a review in an overseas music-production magazine.

Sound On Sound (April 2019)

• Praised the sound as good and the screen as excellent
• Praised the new features for making it very easy to match the loudness standards of streaming and other services
• Listed no cons

Source: Sound On Sound review

Pro-L 2 system requirements and getting started

Operating system	Windows / Mac
Plug-in formats	VST, VST3, AU, CLAP, AAX
Trial	30-day trial available
OBS (streaming)	Works as it is (VST2 is listed)

Checked on the manufacturer’s official pages on September 27, 2026.

Compared with other limiter plug-ins

Click a heading to sort. On a phone, the table scrolls sideways.

Read next

• smart:limit: features and rating (rank S)
• TDR Limiter 6 GE: features and rating (rank S)
• pure:limit: features and rating (rank A)
• Oxford Limiter: features and rating (rank B)