Correction, 2026-10-02: the FAQ said ElevenLabs Sound Effects on 8frame costs 5 credits, about $0.05, per generation. It bills 1 to 6 credits by the length you set: up to 4 seconds 1, up to 8 seconds 2, up to 12 seconds 3, up to 17 seconds 5, up to 22 seconds 6. The page discussed free tiers and free libraries without naming any; it now gives the free plans of ElevenLabs and Stable Audio and the licence terms of Freesound and Pixabay, checked on 2026-10-02, with sources. We removed claims we had not measured: that recordings carry detail that generation "smooths out", that anyone who knows an object notices a generated version, that non-commercial is "the most common misread", that room tone is "skipped constantly" and that effects at dialogue level are "the most common amateur tell". The page also had no Sources section and did not end with our standard closing line.
For a sound with a name (a door, footsteps, rain on a window), the free answer is usually a library, not a generator: a recording of the real thing probably exists, and auditioning it costs nothing. Generation earns its place in the opposite case: the sound that does not exist, the one you cannot describe well enough to search for, or one that has to fit an exact length. Decide which case you are in before you compare tools.
We have not run a side-by-side quality test of any tool here, so this guide does not rank sound. It covers what the free plans allow, how free libraries license their files, and what a generated effect costs on 8frame. Disclosure: 8frame is our product, it is not a free tool (a new account starts with no credits), and commercial use is cleared on paid plans.
TL;DR
- Common sounds (doors, footsteps, ambience, UI clicks): search a free library first
- Specific, imaginary or exactly-timed sounds: generate
- Free generators: ElevenLabs' free plan has 10k credits a month, which its plan table puts at 250 seconds of sound effects, with no commercial licence; Stable Audio's free plan has 50 credits a month for "Personal, non-commercial use"
- Licence trap: free libraries license per file. On Freesound, one sound can be CC0 and the next attribution-only or non-commercial. Read the licence on the file, not the site
- On 8frame: ElevenLabs Sound Effects bills 1 to 6 credits by length, about $0.01 to $0.06 at pack rate (1 credit up to 4 seconds, 6 credits up to 22 seconds)
- A cheap win that is not an effect at all: room tone and a proper mix
Libraries versus generation
Use a library when the sound is a real-world event with a name. A door closing, rain on a window, a car passing. A recording of the real event probably exists, and a search is often faster than writing and auditioning prompts.
Generate when the sound is imaginary, brand-specific, or has to fit an exact length (the 8frame tool takes 0.5 to 22 seconds). Also when a library search has failed twice: a sign that what you want may not be a named category.
Free generators, checked 2026-10-02
What each tool's own pricing page says:
- ElevenLabs: the free plan has 10k credits a month and includes Sound Effects. ElevenLabs charges 200 credits per generation when its AI picks the length, or 40 credits per second when you set the length yourself, up to 22 seconds; its plan table puts the free allowance at "250 seconds of Sound Effects". The free plan has no commercial licence: the Commercial License starts on Starter, $6 a month.
- Stable Audio: the web app makes "music and sound effects". The free plan has 50 credits a month, which Stability puts at "About 12 full-mix generations", for "Personal, non-commercial use". The commercial license starts on Solo at $12 a month.
Both free plans rule out commercial use, and a brand video, a monetised channel or a client ad is commercial use. Read the tier's own terms again on the day you sign up.
Licence traps in free libraries
Licensed per file. Freesound lets each uploader pick one of three Creative Commons licences for each sound. Its own summary: with CC0 "you can do pretty much what you want with the sound"; with Attribution "you should always mention the original creators of the sounds when you use them"; Attribution NonCommercial "works like attribution, but you can't earn any money with the piece of work you create". Two results on the same search page can carry different terms.
Attribution required. Easy to breach on social, where a short video may have no obvious place for a credit. Freesound suggests a credit line naming each sound, its author, its link and its licence.
Non-commercial only. A brand video is commercial use even if the video itself sells nothing.
Free to use, not to resell. Pixabay's Content License lets you use content for free without crediting the author, but "You cannot sell or distribute Content (either in digital or physical form) on a Standalone basis", meaning with no creative effort applied. Inside your edit is fine; passing the file on more or less as it is, in a sound pack for instance, is what that clause rules out.
"Royalty free" is not "free". It usually means no ongoing royalties once you have the licence, not that the licence costs nothing.
Read the licence attached to the individual file, because large sites host files under several different terms.
What it costs on 8frame
Canon 8frame prices; a credit is about $0.01 at pack rate. ElevenLabs Sound Effects bills by the length you set:
| Length | Credits | About |
|---|---|---|
| Up to 4 seconds | 1 | $0.01 |
| Up to 8 seconds | 2 | $0.02 |
| Up to 12 seconds | 3 | $0.03 |
| Up to 17 seconds | 5 | $0.05 |
| Up to 22 seconds | 6 | $0.06 |
The tool takes 0.5 to 22 seconds and a prompt of 3 to 500 characters. Twenty 4-second options cost 20 credits, about $0.20; twenty 22-second ones cost 120, about $1.20. That changes the workflow: prompt several variants against the picture rather than settling for the first acceptable one, and keep the length as short as the moment needs.
Where the effect goes: lay it on the Video Editor timeline, which has sound layers. Montage joins the picture only: the merged file has no sound, so add effects, music and dialogue in the Video Editor after the cut (or in your own editor).
Where generation fits, and where to check hardest
Worth trying: ambiences and beds, abstract whooshes and transitions, impacts, textures, anything stylised, where nobody expects one exact real-world sound.
Check hardest: anything with a precise physical identity. A specific camera shutter, a specific engine, a recognisable device. If your audience knows the object, compare the take with a recording of the real thing before you use it, and use the recording if the take does not hold up.
The thing that improves your audio cheaply
Not effects. Three habits:
Room tone. Thirty seconds of the space, laid under everything, helps the cuts in a scene sit together. If you are on set, recording it costs nothing.
Levels. Effects at the same level as dialogue compete with it. Set the dialogue first and bring the effects in under it.
Silence. A beat with nothing in it before an impact gives the impact room.
FAQ
Are AI sound effects free? Some tools have free plans: ElevenLabs' free plan has 10k credits a month, which it puts at 250 seconds of sound effects, and Stable Audio's has 50 credits a month, both without commercial use. On 8frame, generation is paid: ElevenLabs Sound Effects bills 1 to 6 credits by length, about $0.01 to $0.06, and a new account starts with no credits.
Can I use generated sound effects commercially? On 8frame, commercial use of output is cleared on paid plans. The free plans of ElevenLabs and Stable Audio do not include it; their commercial licences start on Starter ($6 a month) and Solo ($12 a month). Check the terms per tool before shipping.
How long can a generated sound effect be on 8frame? 0.5 to 22 seconds per generation. Up to 4 seconds bills 1 credit; 22 seconds bills 6.
Do free sound libraries require attribution? It depends on the file. On Freesound, CC0 sounds do not; Attribution and Attribution NonCommercial sounds do. Pixabay's licence does not require attribution, but it bars selling or distributing content on a standalone basis.
Library or generated for a brand video? Library for real-world sounds with a name, generated for beds, transitions and anything that has to fit an exact length, and a proper mix for both.
Related
- Best free AI music generators: the same licensing trade across music tools
- Best free AI beat generators: instrumental beds, with sound effects layered over
- Best free AI lofi generators
- Why does my AI video have no sound?
Sources
- ElevenLabs plans and credit costs: free plan 10k credits a month with Sound Effects, "250 seconds of Sound Effects" on the free plan, 200 credits per generation when the AI picks the length or 40 credits per second when you set it (maximum 22 seconds), Commercial License from Starter at $6 a month: elevenlabs.io/pricing, checked 2026-10-02
- Stable Audio plans: free plan 50 credits a month, "About 12 full-mix generations", "Personal, non-commercial use", Solo $12 a month with a commercial license: stableaudio.com/pricing; "Create music and sound effects" in the web app: stableaudio.com, both checked 2026-10-02
- Freesound FAQ, Licenses (three Creative Commons licences chosen per sound, the quoted summaries, the suggested credit line): freesound.org/help/faq, checked 2026-10-02
- Pixabay Content License summary (free use, no attribution required, no standalone sale or distribution): pixabay.com/service/license-summary, checked 2026-10-02
- 8frame prices and limits: ElevenLabs Sound Effects length table (1, 2, 3, 5 and 6 credits up to 4, 8, 12, 17 and 22 seconds), 0.5 to 22 seconds, prompt 3 to 500 characters: 8frame tool registry and front-end schema, checked 2026-10-02
- Video Editor sound layers; Montage output has no sound; new accounts start with no credits; commercial use cleared on paid plans: 8frame content fact sheet, checked 2026-10-02
Search first, generate second, and lay room tone under everything.
Try it without signing up: the 8frame canvas opens on a real board. The canvas is free and unlimited; generation is paid from $19/month.